Require a --yes argument before actually cleaning data

New option --nshift controls how many shifted FFT windows to perform
per period.  "nilm-prep -N 2" is similar to old prep behavior.  Note
that this is redundant information and takes up extra storage space,
though.

.gitignore

@@ -1,3 +1,6 @@
+oldprep
+newprep
+*.dat
 build/
 *.pyc
 dist/

Makefile

@@ -1,11 +1,47 @@
-test:
-	nilmtool remove /lees-compressor/noleak/raw~4 -s 2000 -e 2020
-	nilmtool remove /lees-compressor/noleak/raw~16	 -s 2000 -e 2020
-	python nilmtools/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/noleak/raw /lees-compressor/noleak/raw~4
-	python nilmtools/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/noleak/raw~4 /lees-compressor/noleak/raw~16
+#URL="http://bucket.mit.edu:8080/nilmdb"
+URL="http://localhost/nilmdb"
 
 all:
+ifeq ($(INSIDE_EMACS), t)
+	@make test
+else
 	@echo "Try 'make install'"
+endif
+
+test: test_cleanup
+
+test_cleanup:
+	src/cleanup.py -e extras/cleanup.cfg
+	src/cleanup.py extras/cleanup.cfg
+
+test_insert:
+	@make install >/dev/null
+	src/insert.py --file --dry-run  /test/foo </dev/null
+
+test_copy:
+	@make install >/dev/null
+	src/copy_wildcard.py -U "http://nilmdb.com/bucket/" -D /lees*
+
+test_prep:
+	@make install >/dev/null
+	-nilmtool destroy -R /test/raw
+	-nilmtool destroy -R /test/sinefit
+	-nilmtool destroy -R /test/prep
+	nilmtool create /test/raw float32_2
+	nilmtool create /test/sinefit float32_3
+	nilmtool create /test/prep float32_8
+	nilmtool insert -s '@0' -t -r 8000 /test/raw /tmp/raw.dat
+	src/sinefit.py -c 1 /test/raw /test/sinefit
+	src/prep.py -c 2 /test/raw /test/sinefit /test/prep
+	nilmtool extract -s min -e max /test/prep | head -20
+
+test_decimate:
+	-@nilmtool destroy /lees-compressor/no-leak/raw/4 || true
+	-@nilmtool destroy /lees-compressor/no-leak/raw/16 || true
+	-@nilmtool create /lees-compressor/no-leak/raw/4 float32_18 || true
+	-@nilmtool create /lees-compressor/no-leak/raw/16 float32_18 || true
+	time python src/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/1 /lees-compressor/no-leak/raw/4
+	python src/decimate.py -s '2013-02-04 18:10:00' -e '2013-02-04 18:11:00' /lees-compressor/no-leak/raw/4 /lees-compressor/no-leak/raw/16
 
 version:
 	python setup.py version

README.txt

@@ -6,9 +6,22 @@ Prerequisites:
 
   # Runtime and build environments
   sudo apt-get install python2.7 python2.7-dev python-setuptools
+  sudo apt-get install python-numpy python-scipy python-matplotlib
 
-  nilmdb (1.3.1+)
+  nilmdb (1.5.0+)
 
 Install:
 
   python setup.py install
+
+Building new tools:
+
+  The tools in this package are meant to be installed with
+  "python setup.py install".  If you want to make a new one,
+  an easier way to develop would be to first install this package,
+  and then copy a specific script like "src/sinefit.py" to a new
+  location, and modify it as desired.
+
+  To add a tool to the package, place it in "src/" and add the
+  appropriate configuration to "setup.py".
+

extras/cleanup.cfg

@@ -0,0 +1,22 @@
+[/lees-compressor/no-leak/prep]
+keep = 2d
+rate = 60
+
+[*/raw]
+keep = 2d
+
+[*/something]
+rate = 10
+
+[*/sinefit]
+keep = 1w
+decimated = False
+
+[/test/raw]
+keep = 0.01d
+
+[/test/sinefit]
+keep = 0.01d
+
+[/test/prep]
+keep = 0.01d

nilmtools/copy.py

@@ -1,36 +0,0 @@
-#!/usr/bin/python
-
-import nilmtools.filter
-import nilmdb.client
-import numpy as np
-import sys
-
-def main():
-    f = nilmtools.filter.Filter()
-    parser = f.setup_parser("Copy a stream")
-
-    # Parse arguments
-    try:
-        args = f.parse_args()
-    except nilmtools.filter.MissingDestination as e:
-        print "Source is %s (%s)" % (e.src, e.layout)
-        print "Destination %s doesn't exist" % (e.dest)
-        print "You could make it with a command like:"
-        print "  nilmtool create", e.dest, e.layout
-        raise SystemExit(1)
-
-    # Copy metadata
-    meta = f.client.stream_get_metadata(args.srcpath)
-    f.check_dest_metadata(meta)
-
-    # Copy all rows of data as ASCII strings
-    extractor = nilmdb.client.Client(args.url).stream_extract
-    inserter = nilmdb.client.Client(args.url).stream_insert_context
-    for (start, end) in f.intervals():
-        print "Processing", f.interval_string((start, end))
-        with inserter(args.destpath, start, end) as insert_ctx:
-            for row in extractor(args.srcpath, start, end):
-                insert_ctx.insert(row + "\n")
-
-if __name__ == "__main__":
-    main()

nilmtools/decimate.py

@@ -1,70 +0,0 @@
-#!/usr/bin/python
-
-import nilmtools.filter
-import nilmdb.client
-import numpy as np
-
-def main():
-    f = nilmtools.filter.Filter()
-    parser = f.setup_parser("Decimate a stream")
-    group = parser.add_argument_group("Decimate options")
-    group.add_argument('-f', '--factor', action='store', default=4, type=int,
-                       help='Decimation factor (default: %(default)s)')
-    # Parse arguments
-    try:
-        args = f.parse_args()
-    except nilmtools.filter.MissingDestination as e:
-        # If no destination, suggest how to create it by figuring out
-        # a recommended layout.
-        print "Source is %s (%s)" % (e.src, e.layout)
-        print "Destination %s doesn't exist" % (e.dest)
-        if "decimate_source" in f.client.stream_get_metadata(e.src):
-            rec = e.layout
-        elif 'int32' in e.layout_type or 'float64' in e.layout_type:
-            rec = 'float64_' + str(e.layout_count * 3)
-        else:
-            rec = 'float32_' + str(e.layout_count * 3)
-        print "You could make it with a command like:"
-        print "  nilmtool create", e.dest, rec
-        raise SystemExit(1)
-
-    f.check_dest_metadata({ "decimate_source": args.srcpath,
-                            "decimate_factor": args.factor })
-
-    # If source is decimated, we have to decimate a bit differently
-    if "decimate_source" in f.client.stream_get_metadata(args.srcpath):
-        f.process(function = decimate_again, rows = args.factor)
-    else:
-        f.process(function = decimate_first, rows = args.factor)
-
-def decimate_first(data):
-    """Decimate original data -- result has 3 times as many columns"""
-    data = np.array(data)
-    rows, cols = data.shape
-    n = cols - 1
-    out = np.zeros(1 + 3 * n)
-
-    out[0] = np.mean(data[:, 0], 0)
-    out[    1 : n+1  ] = np.mean(data[:, 1 : n+1], 0)
-    out[  n+1 : 2*n+1] = np.min( data[:, 1 : n+1], 0)
-    out[2*n+1 : 3*n+1] = np.max( data[:, 1 : n+1], 0)
-
-    return [out]
-
-def decimate_again(data):
-    """Decimate already-decimated data -- result has the same number
-    of columns"""
-    data = np.array(data)
-    rows, cols = data.shape
-    n = (cols - 1) // 3
-    out = np.zeros(1 + 3 * n)
-
-    out[0] = np.mean(data[:, 0], 0)
-    out[    1 : n+1  ] = np.mean(data[:,     1 :   n+1], 0)
-    out[  n+1 : 2*n+1] = np.min( data[:,   n+1 : 2*n+1], 0)
-    out[2*n+1 : 3*n+1] = np.max( data[:, 2*n+1 : 3*n+1], 0)
-
-    return [out]
-
-if __name__ == "__main__":
-    main()

nilmtools/filter.py

@@ -1,219 +0,0 @@
-#!/usr/bin/python
-
-import nilmdb.client
-from nilmdb.utils.printf import *
-from nilmdb.utils.time import parse_time, format_time
-
-import nilmtools
-
-import itertools
-import time
-import sys
-import re
-import argparse
-
-class MissingDestination(Exception):
-    def __init__(self, src, layout, dest):
-        self.src = src
-        self.layout = layout
-        self.layout_type = layout.split('_')[0]
-        self.layout_count = int(layout.split('_')[1])
-        self.dest = dest
-        Exception.__init__(self, "destination path " + dest + " not found")
-
-class Filter(object):
-
-    def __init__(self):
-        self._parser = None
-        self._args = None
-        self._client = None
-        self._using_client = False
-        self.srcinfo = None
-        self.destinfo = None
-
-    @property
-    def client(self):
-        if self._using_client:
-            raise Exception("Filter client is in use; make another")
-        return self._client
-
-    def setup_parser(self, description = "Filter data"):
-        parser = argparse.ArgumentParser(
-            formatter_class = argparse.RawDescriptionHelpFormatter,
-            version = nilmtools.__version__,
-            description = description)
-        group = parser.add_argument_group("General filter arguments")
-        group.add_argument("-u", "--url", action="store",
-                           default="http://localhost:12380/",
-                           help="Server URL (default: %(default)s)")
-        group.add_argument("-D", "--dry-run", action="store_true",
-                           default = False,
-                           help="Just print intervals that would be "
-                           "processed")
-        group.add_argument("-s", "--start",
-                           metavar="TIME", type=self.arg_time,
-                           help="Starting timestamp for intervals "
-                           "(free-form, inclusive)")
-        group.add_argument("-e", "--end",
-                           metavar="TIME", type=self.arg_time,
-                           help="Ending timestamp for intervals "
-                           "(free-form, noninclusive)")
-        group.add_argument("srcpath", action="store",
-                           help="Path of source stream, e.g. /foo/bar")
-        group.add_argument("destpath", action="store",
-                           help="Path of destination stream, e.g. /foo/bar")
-        self._parser = parser
-        return parser
-
-    def parse_args(self):
-        args = self._parser.parse_args()
-        self._args = args
-        self._client = nilmdb.client.Client(args.url)
-
-        if args.srcpath == args.destpath:
-            raise Exception("source and destination path must be different")
-
-        # Open and print info about the streams
-        src = self._client.stream_list(args.srcpath, extended = True)
-        if len(src) != 1:
-            raise Exception("source path " + args.srcpath + " not found")
-        self.srcinfo = src[0]
-
-        dest = self._client.stream_list(args.destpath, extended = True)
-        if len(dest) != 1:
-            raise MissingDestination(self.srcinfo[0], self.srcinfo[1],
-                                     args.destpath)
-        self.destinfo = dest[0]
-
-        print "Source:", self.stream_info_string(self.srcinfo)
-        print "  Dest:", self.stream_info_string(self.destinfo)
-
-        if args.dry_run:
-            for interval in self.intervals():
-                print self.interval_string(interval)
-            raise SystemExit(0)
-
-        return args
-
-    def intervals(self):
-        """Generate all the intervals that this filter should process"""
-        self._using_client = True
-        for i in self._client.stream_intervals(
-            self._args.srcpath, diffpath = self._args.destpath,
-            start = self._args.start, end = self._args.end):
-            yield i
-        self._using_client = False
-
-    # Misc helpers
-    def arg_time(self, toparse):
-        """Parse a time string argument"""
-        try:
-            return nilmdb.utils.time.parse_time(toparse).totimestamp()
-        except ValueError as e:
-            raise argparse.ArgumentTypeError(sprintf("%s \"%s\"",
-                                                     str(e), toparse))
-
-    def stream_info_string(self, info):
-        """Print stream info as a string"""
-        return sprintf("%s (%s), %.2fM rows, %.2f hours",
-                       info[0], info[1], info[4] / 1e6, info[5] / 3600)
-
-    def interval_string(self, interval):
-        """Print interval as a string"""
-        return sprintf("[ %s -> %s ]", format_time(interval[0]),
-                       format_time(interval[1]))
-
-    def check_dest_metadata(self, data):
-        """See if the metadata jives, and complain if it doesn't.  If
-        there's no conflict, update the metadata to match 'data'."""
-        metadata = self._client.stream_get_metadata(self._args.destpath)
-        rows = self.destinfo[4]
-        for key in data:
-            wanted = str(data[key])
-            val = metadata.get(key, wanted)
-            if val != wanted and rows > 0:
-                m =  "Metadata in destination stream:\n"
-                m += "  %s = %s\n" % (key, val)
-                m += "doesn't match desired data:\n"
-                m += "  %s = %s\n" % (key, wanted)
-                m += "Refusing to change it.  You can change the stream's "
-                m += "metadata manually, or\n"
-                m += "remove existing data from the stream, to prevent "
-                m += "this error.\n"
-                raise Exception(m)
-        # All good -- write the metadata in case it's not already there
-        self._client.stream_update_metadata(self._args.destpath, data)
-
-    # Main processing helper
-    def process(self, function, rows, args = None, partial = False):
-        """Process data in chunks of 'rows' data at a time.
-
-        function: function to process the data
-        rows: maximum number of rows to pass to 'function' at once
-        args: tuple containing extra arguments to pass to 'function'
-        partial: if true, less than 'rows' may be passed to 'function'.
-                 if false, partial data at the end of an interval will
-                 be dropped.
-
-        'function' should be defined like:
-            function(data, *args)
-        It will be passed an array containing up to 'rows' rows of
-        data from the source stream, and any arguments passed in
-        'args'.  It should transform the data as desired, and return a
-        new array of data, which will be inserted into the destination
-        stream.
-        """
-        if args is None:
-            args = []
-        extractor = nilmdb.client.Client(self._args.url).stream_extract
-        inserter = nilmdb.client.Client(self._args.url).stream_insert_context
-        src = self._args.srcpath
-        dest = self._args.destpath
-
-        # Figure out how to format output data
-        dest_layout = self.destinfo[1].split('_')[1]
-        def int_formatter(row):
-            return ("%.6f " % row[0]) + " ".join(str(int(x)) for x in row[1:])
-        def float_formatter(row):
-            return ("%.6f " % row[0]) + " ".join(repr(x) for x in row[1:])
-        if "int" in dest_layout:
-            formatter = int_formatter
-        else:
-            formatter = float_formatter
-
-        for (start, end) in self.intervals():
-            print "Processing", self.interval_string((start, end))
-            with inserter(dest, start, end) as insert_ctx:
-                src_array = []
-                for line in extractor(src, start, end):
-                    # Read in data
-                    src_array.append([ float(x) for x in line.split() ])
-
-                    if len(src_array) == rows:
-                        # Pass through filter function
-                        dest_array = function(src_array, *args)
-
-                        # Write result to destination
-                        out = [ formatter(row) for row in dest_array ]
-                        insert_ctx.insert("\n".join(out) + "\n")
-
-                        # Clear source array
-                        src_array = []
-
-                # Take care of partial chunk
-                if len(src_array) and partial:
-                    dest_array = function(src_array, *args)
-                    out = [ formatter(row) for row in dest_array ]
-                    insert_ctx.insert("\n".join(out) + "\n")
-
-def main():
-    # This is just a dummy function; actual filters can use the other
-    # functions to prepare stuff, and then do something with the data.
-    f = Filter()
-    parser = f.setup_parser()
-    args = f.parse_args()
-    for (start, end) in f.intervals():
-        print "Generic filter: need to handle", start, " to ", end
-
-if __name__ == "__main__":
-    main()

nilmtools/insert.py

@@ -1,173 +0,0 @@
-#!/usr/bin/python
-
-import nilmdb.client
-from nilmdb.utils.printf import *
-from nilmdb.utils.time import parse_time, format_time
-
-import nilmtools
-import time
-import sys
-import re
-import argparse
-import subprocess
-
-class ParseError(Exception):
-    def __init__(self, filename, error):
-        msg = filename + ": " + error
-        super(ParseError, self).__init__(msg)
-
-def parse_args():
-    parser = argparse.ArgumentParser(
-        formatter_class = argparse.RawDescriptionHelpFormatter,
-        version = nilmtools.__version__,
-        description = """\
-    Insert data from ethstream, either live (using the system time as a
-    reference) or prerecorded (using comments in the file as a reference).
-
-    The data is assumed to have been recorded at the specified rate.
-    Small discrepencies between the accumulated timestamps and the
-    reference time are ignored; larger discrepencies cause gaps to be
-    created in the stream.  Overlapping data returns an error.
-    """)
-    parser.add_argument("-u", "--url", action="store",
-                        default="http://localhost:12380/",
-                        help="NilmDB server URL (default: %(default)s)")
-    parser.add_argument("-r", "--rate", action="store", default=8000,
-                        type=float,
-                        help="Data rate in Hz (default: %(default)s)")
-    parser.add_argument("-l", "--live", action="store_true",
-                        help="Live capture; use system time to verify rate")
-    parser.add_argument("path", action="store",
-                        help="Path of stream, e.g. /foo/bar")
-    parser.add_argument("infile", type=argparse.FileType('r'), nargs='*',
-                        default=[sys.stdin],
-                        help="Input files (default: stdin)")
-    args = parser.parse_args()
-
-    printf("Stream path: %s\n", args.path)
-    printf("  Data rate: %s Hz\n", repr(args.rate))
-
-    return args
-
-def main(args = None):
-    if args is None:
-        args = parse_args()
-
-    client = nilmdb.client.Client(args.url)
-
-    # Local copies to save dictionary lookups
-    live = args.live
-
-    # data_ts is the timestamp that we'll use for the current line
-    data_ts_base = 0
-    data_ts_inc = 0
-    data_ts_step = 1.0 / args.rate
-
-    # clock_ts is the imprecise "real" timestamp (from the filename,
-    # comments, or or system clock)
-    clock_ts = None
-
-    def print_clock_updated():
-        printf("Clock time updated to %s\n", format_time(clock_ts))
-        if data_ts_base != 0:
-            diff = data_ts - clock_ts
-            if diff >= 0:
-                printf("  (data timestamp ahead by %.6f sec)\n", diff)
-            else:
-                printf("  (data timestamp behind by %.6f sec)\n", -diff)
-
-    with client.stream_insert_context(args.path) as stream:
-        for f in args.infile:
-            filename = f.name
-            printf("Processing %s\n", filename)
-
-            # If the filename ends in .gz, open it with gzcat instead.
-            if filename.endswith(".gz"):
-                p = subprocess.Popen(["gzip", "-dc"],
-                                     stdin = f, stdout = subprocess.PIPE)
-                f = p.stdout
-
-            # Try to get a real timestamp from the filename
-            try:
-                # Subtract 1 hour because files are created at the end
-                # of the hour.  Hopefully, we'll be able to use
-                # internal comments and this value won't matter anyway.
-                clock_ts = parse_time(filename).totimestamp() - 3600
-                print_clock_updated()
-            except ValueError:
-                pass
-
-            truncated_lines = 0
-
-            # Read each line
-            for line in f:
-                data_ts = data_ts_base + data_ts_inc * data_ts_step
-
-                # If no content other than the newline, skip it
-                if len(line) <= 1:
-                    continue
-
-                # If line starts with a comment, look for a timestamp
-                if line[0] == '#':
-                    try:
-                        clock_ts = parse_time(line[1:]).totimestamp()
-                        print_clock_updated()
-                    except ValueError:
-                        pass
-                    continue
-
-                # If inserting live, use clock timestamp
-                if live:
-                    clock_ts = time.time()
-
-                # If we have a real timestamp, compare it to the data
-                # timestamp, and make sure things match up.
-                if clock_ts is not None:
-                    if (data_ts - 10) > clock_ts:
-                        # Accumulated line timestamps are in the future.
-                        # If we were to set data_ts=clock_ts, we'd create
-                        # an overlap, so we have to just bail out here.
-                        err = sprintf("Data is coming in too fast: data time "
-                                      "is %s but clock time is only %s",
-                                      format_time(data_ts),
-                                      format_time(clock_ts))
-                        raise ParseError(filename, err)
-
-                    if (data_ts + 10) < clock_ts:
-                        # Accumulated line timetamps are in the past.  We
-                        # can just skip some time and leave a gap in the
-                        # data.
-                        if data_ts_base != 0:
-                            printf("Skipping data timestamp forward from "
-                                   "%s to %s to match clock time\n",
-                                   format_time(data_ts),
-                                   format_time(clock_ts))
-                        stream.finalize()
-                        data_ts_base = data_ts = clock_ts
-                        data_ts_inc = 0
-
-                    # Don't use this clock time anymore until we update it
-                    clock_ts = None
-
-                if data_ts_base == 0:
-                    raise ParseError(filename, "No idea what timestamp to use")
-
-                # This line is legit, so increment timestamp
-                data_ts_inc += 1
-
-                # Once in a while a line might be truncated, if we're at
-                # the end of a file.  Ignore it, but if we ignore too many,
-                # bail out.
-                if line[-1] != '\n':
-                    truncated_lines += 1
-                    if truncated_lines > 3:
-                        raise ParseError(filename, "too many short lines")
-                    printf("Ignoring short line in %s\n", filename)
-                    continue
-
-                # Insert it
-                stream.insert("%.6f %s" % (data_ts, line))
-    print "Done"
-
-if __name__ == "__main__":
-    main()

setup.py

@@ -30,7 +30,7 @@ except ImportError:
 # Versioneer manages version numbers from git tags.
 # https://github.com/warner/python-versioneer
 import versioneer
-versioneer.versionfile_source = 'nilmtools/_version.py'
+versioneer.versionfile_source = 'src/_version.py'
 versioneer.versionfile_build = 'nilmtools/_version.py'
 versioneer.tag_prefix = 'nilmtools-'
 versioneer.parentdir_prefix = 'nilmtools-'
@@ -61,15 +61,24 @@ setup(name='nilmtools',
       long_description = "NILM Database Tools",
       license = "Proprietary",
       author_email = 'jim@jtan.com',
-      install_requires = [ 'nilmdb >= 1.3.0',
+      install_requires = [ 'nilmdb >= 1.5.0',
+                           'numpy',
+                           'scipy',
+                           'matplotlib',
                            ],
       packages = [ 'nilmtools',
                    ],
+      package_dir = { 'nilmtools': 'src' },
       entry_points = {
           'console_scripts': [
               'nilm-decimate = nilmtools.decimate:main',
+              'nilm-decimate-auto = nilmtools.decimate_auto:main',
               'nilm-insert = nilmtools.insert:main',
-              'nilm-copy = nilmtools.copy:main',
+              'nilm-copy = nilmtools.copy_one:main',
+              'nilm-prep = nilmtools.prep:main',
+              'nilm-copy-wildcard = nilmtools.copy_wildcard:main',
+              'nilm-sinefit = nilmtools.sinefit:main',
+              'nilm-cleanup = nilmtools.cleanup:main',
               ],
           },
       zip_safe = False,

src/_version.py

@@ -181,7 +181,7 @@ def versions_from_parentdir(parentdir_prefix, versionfile_source, verbose=False)
 
 tag_prefix = "nilmtools-"
 parentdir_prefix = "nilmtools-"
-versionfile_source = "nilmtools/_version.py"
+versionfile_source = "src/_version.py"
 
 def get_versions(default={"version": "unknown", "full": ""}, verbose=False):
     variables = { "refnames": git_refnames, "full": git_full }

src/cleanup.py

@@ -0,0 +1,254 @@
+#!/usr/bin/python
+
+from nilmdb.utils.printf import *
+from nilmdb.utils.time import (parse_time, timestamp_to_human,
+                               timestamp_to_seconds, seconds_to_timestamp)
+from nilmdb.utils.diskusage import human_size
+from nilmdb.utils.interval import Interval
+import nilmdb.client
+import nilmdb.client.numpyclient
+import nilmtools
+import argparse
+import ConfigParser
+import sys
+import collections
+import fnmatch
+import re
+
+def warn(msg, *args):
+    fprintf(sys.stderr, "warning: " + msg + "\n", *args)
+
+class TimePeriod(object):
+    _units = { 'h': ('hour',  60*60),
+               'd': ('day',   60*60*24),
+               'w': ('week',  60*60*24*7),
+               'm': ('month', 60*60*24*30),
+               'y': ('year',  60*60*24*365) }
+
+    def __init__(self, val):
+        for u in self._units:
+            if val.endswith(u):
+                self.unit = self._units[u][0]
+                self.scale = self._units[u][1]
+                self.count = float(val[:-len(u)])
+                break
+        else:
+            raise ValueError("unknown units: " + units)
+
+    def seconds(self):
+        return self.count * self.scale
+
+    def describe_seconds(self, seconds):
+        count = seconds / self.scale
+        units = self.unit if count == 1 else (self.unit + "s")
+        if count == int(count):
+            return sprintf("%d %s", count, units)
+        else:
+            return sprintf("%.2f %s", count, units)
+
+    def __str__(self):
+        return self.describe_seconds(self.seconds())
+
+class StreamCleanupConfig(object):
+    def __init__(self, info):
+        self.path = info[0]
+        self.layout = info[1]
+        if info[4] != 0 and info[5] != 0:
+            self.rate = info[4] / timestamp_to_seconds(info[5])
+        else:
+            self.rate = None
+        self.keep = None
+        self.clean_decimated = True
+        self.decimated_from = None
+        self.also_clean_paths = []
+
+def main(argv = None):
+    parser = argparse.ArgumentParser(
+        formatter_class = argparse.RawDescriptionHelpFormatter,
+        version = nilmtools.__version__,
+        description = """\
+    Clean up old data from streams using a configuration file to specify
+    which data to remove.
+
+    The format of the config file is as follows:
+
+      [/stream/path]
+      keep = 3w         # keep up to 3 weeks of data
+      rate = 8000       # optional, used for the --estimate option
+      decimated = false # whether to delete decimated data too (default true)
+
+      [*/prep]
+      keep = 3.5m       # or 2520h or 105d or 15w or 0.29y
+
+    The suffix for 'keep' is 'h' for hours, 'd' for days, 'w' for weeks,
+    'm' for months, or 'y' for years.
+
+    Streams paths may include wildcards.  If a path is matched by more than
+    one config section, data from the last config section counts.
+
+    Decimated streams (paths containing '~decim-') are treated specially:
+      - They don't match wildcards
+      - When deleting data from a parent stream, data is also deleted
+        from its decimated streams, unless decimated=false
+
+    Rate is optional and is only used for the --estimate option.
+    """)
+    parser.add_argument("-u", "--url", action="store",
+                        default="http://localhost/nilmdb/",
+                        help="NilmDB server URL (default: %(default)s)")
+    parser.add_argument("-y", "--yes", action="store_true",
+                        default = False,
+                        help="Actually remove the data (default: no)")
+    parser.add_argument("-e", "--estimate", action="store_true",
+                        default = False,
+                        help="Estimate how much disk space will be used")
+    parser.add_argument("configfile", type=argparse.FileType('r'),
+                        help="Configuration file")
+    args = parser.parse_args(argv)
+
+    # Parse config file
+    config = ConfigParser.RawConfigParser()
+    config.readfp(args.configfile)
+
+    # List all streams
+    client = nilmdb.client.Client(args.url)
+    streamlist = client.stream_list(extended = True)
+
+    # Create config objects
+    streams = collections.OrderedDict()
+    for s in streamlist:
+        streams[s[0]] = StreamCleanupConfig(s)
+        m = re.search(r"^(.*)~decim-[0-9]+$", s[0])
+        if m:
+            streams[s[0]].decimated_from = m.group(1)
+
+    # Build up configuration
+    for section in config.sections():
+        matched = False
+        for path in streams.iterkeys():
+            # Decimated streams only allow exact matches
+            if streams[path].decimated_from and path != section:
+                continue
+            if not fnmatch.fnmatch(path, section):
+                continue
+            matched = True
+            options = config.options(section)
+
+            # Keep period (days, weeks, months, years)
+            if 'keep' in options:
+                streams[path].keep = TimePeriod(config.get(section, 'keep'))
+                options.remove('keep')
+
+            # Rate
+            if 'rate' in options:
+                streams[path].rate = config.getfloat(section, 'rate')
+                options.remove('rate')
+
+            # Decimated
+            if 'decimated' in options:
+                val = config.getboolean(section, 'decimated')
+                streams[path].clean_decimated = val
+                options.remove('decimated')
+
+            for leftover in options:
+                warn("option '%s' for '%s' is unknown", leftover, section)
+
+        if not matched:
+            warn("config for '%s' did not match any existing streams", section)
+
+    # List all decimated streams in the parent stream's info
+    for path in streams.keys():
+        src = streams[path].decimated_from
+        if src and src in streams:
+            if streams[src].clean_decimated:
+                streams[src].also_clean_paths.append(path)
+                del streams[path]
+
+    # Warn about streams that aren't getting cleaned up
+    for path in streams.keys():
+        if streams[path].keep is None or streams[path].keep.seconds() < 0:
+            warn("no config for existing stream '%s'", path)
+            del streams[path]
+
+    if args.estimate:
+        # Estimate disk usage
+        total = 0
+        for path in streams.keys():
+            rate = streams[path].rate
+            if not rate or rate < 0:
+                warn("unable to estimate disk usage for stream '%s' because "
+                     "the data rate is unknown", path)
+                continue
+            printf("%s:\n", path)
+            layout = streams[path].layout
+            dtype = nilmdb.client.numpyclient.layout_to_dtype(layout)
+            per_row = dtype.itemsize
+            per_sec = per_row * rate
+            printf("%17s: %s per row, %s rows per second\n",
+                   "base rate",
+                   human_size(per_row),
+                   round(rate,1))
+            printf("%17s: %s per hour, %s per day\n",
+                   "base size",
+                   human_size(per_sec * 3600),
+                   human_size(per_sec * 3600 * 24))
+
+            # If we'll be cleaning up decimated data, add an
+            # estimation for how much room decimated data takes up.
+            if streams[path].clean_decimated:
+                d_layout = "float32_" + str(3*(int(layout.split('_')[1])))
+                d_dtype = nilmdb.client.numpyclient.layout_to_dtype(d_layout)
+                # Assume the decimations will be a factor of 4
+                # sum_{k=0..inf} (rate / (n^k)) * d_dtype.itemsize
+                d_per_row = d_dtype.itemsize
+                factor = 4.0
+                d_per_sec = d_per_row * (rate / factor) * (1 / (1 - (1/factor)))
+                per_sec += d_per_sec
+                printf("%17s: %s per hour, %s per day\n",
+                       "with decimation",
+                       human_size(per_sec * 3600),
+                       human_size(per_sec * 3600 * 24))
+
+            keep = per_sec * streams[path].keep.seconds()
+            printf("%17s: %s\n\n",
+                   "keep " + str(streams[path].keep), human_size(keep))
+            total += keep
+        printf("Total estimated disk usage for these streams:\n")
+        printf("  %s\n", human_size(total))
+        raise SystemExit(0)
+
+    # Do the cleanup
+    for path in streams:
+        printf("%s: keep %s\n", path, streams[path].keep)
+
+        # Figure out the earliest timestamp we should keep.
+        intervals = [ Interval(start, end) for (start, end) in
+                      reversed(list(client.stream_intervals(path))) ]
+        total = 0
+        keep = seconds_to_timestamp(streams[path].keep.seconds())
+        for i in intervals:
+            total += i.end - i.start
+            if total <= keep:
+                continue
+            remove_before = i.start + (total - keep)
+            break
+        else:
+            printf("  nothing to do (only %s of data present)\n",
+                   streams[path].keep.describe_seconds(
+                       timestamp_to_seconds(total)))
+            continue
+        printf("  removing data before %s\n", timestamp_to_human(remove_before))
+        if args.yes:
+            client.stream_remove(path, None, remove_before)
+        for ap in streams[path].also_clean_paths:
+            printf("  also removing from %s\n", ap)
+            if args.yes:
+                client.stream_remove(ap, None, remove_before)
+
+    # All done
+    if not args.yes:
+        printf("Note: specify --yes to actually perform removals\n")
+    return
+
+if __name__ == "__main__":
+    main()

src/copy_one.py

@@ -0,0 +1,41 @@
+#!/usr/bin/python
+
+# This is called copy_one instead of copy to avoid name conflicts with
+# the Python standard library.
+
+import nilmtools.filter
+import nilmdb.client
+from nilmdb.client.numpyclient import NumpyClient
+import numpy as np
+import sys
+
+def main(argv = None):
+    f = nilmtools.filter.Filter()
+    parser = f.setup_parser("Copy a stream")
+
+    # Parse arguments
+    try:
+        args = f.parse_args(argv)
+    except nilmtools.filter.MissingDestination as e:
+        print "Source is %s (%s)" % (e.src.path, e.src.layout)
+        print "Destination %s doesn't exist" % (e.dest.path)
+        print "You could make it with a command like:"
+        print "  nilmtool -u %s create %s %s" % (e.dest.url,
+                                                 e.dest.path, e.src.layout)
+        raise SystemExit(1)
+
+    # Copy metadata
+    meta = f.client_src.stream_get_metadata(f.src.path)
+    f.check_dest_metadata(meta)
+
+    # Copy all rows of data using the faster Numpy interfaces
+    extractor = NumpyClient(f.src.url).stream_extract_numpy
+    inserter = NumpyClient(f.dest.url).stream_insert_numpy_context
+    for i in f.intervals():
+        print "Processing", f.interval_string(i)
+        with inserter(f.dest.path, i.start, i.end) as insert_ctx:
+            for data in extractor(f.src.path, i.start, i.end):
+                insert_ctx.insert(data)
+
+if __name__ == "__main__":
+    main()

src/copy_wildcard.py

@@ -0,0 +1,70 @@
+#!/usr/bin/python
+
+# Copy streams between NilmDB servers with wildcards
+
+import nilmtools.filter
+import nilmtools.copy_one
+import nilmdb.client
+import argparse
+import fnmatch
+
+def main(argv = None):
+    f = nilmtools.filter.Filter()
+    # Reuse filter's parser, since it handles most options we need.
+    parser = f.setup_parser(description = """\
+    Copy all streams matching the given wildcard from one host to another.
+
+    Example: %(prog)s -u http://host1/nilmdb -U http://host2/nilmdb /sharon/*
+    """, skip_paths = True)
+    parser.add_argument("path", action="store", nargs="+",
+                        help='Wildcard paths to copy')
+    args = parser.parse_args(argv)
+
+    # Verify arguments
+    if args.dest_url is None:
+        parser.error("must provide both source and destination URL")
+    client_src = nilmdb.client.Client(args.url)
+    client_dest = nilmdb.client.Client(args.dest_url)
+    if client_src.geturl() == client_dest.geturl():
+        parser.error("source and destination URL must be different")
+    print "Source URL:", client_src.geturl()
+    print "  Dest URL:", client_dest.geturl()
+
+    # Find matching streams
+    matched = []
+    for path in args.path:
+        matched.extend([s for s in client_src.stream_list(extended = True)
+                        if fnmatch.fnmatch(s[0], path)
+                        and s not in matched])
+
+    # Create destination streams if they don't exist
+    for stream in matched:
+        src = nilmtools.filter.StreamInfo(client_src.geturl(), stream)
+        dest = nilmtools.filter.get_stream_info(client_dest, src.path)
+        if not dest:
+            print "Creating destination stream", src.path
+            client_dest.stream_create(src.path, src.layout)
+
+    # Copy them all by running the "copy" tool as if it were
+    # invoked from the command line.
+    for stream in matched:
+        new_argv = ["--url", client_src.geturl(),
+                     "--dest-url", client_dest.geturl() ]
+        if args.start:
+            new_argv.extend(["--start", "@" + repr(args.start)])
+        if args.end:
+            new_argv.extend(["--end", "@" + repr(args.end)])
+        if args.dry_run:
+            new_argv.extend(["--dry-run"])
+        if args.force_metadata:
+            new_argv.extend(["--force-metadata"])
+        new_argv.extend([stream[0], stream[0]])
+        try:
+            nilmtools.copy_one.main(new_argv)
+        except SystemExit as e:
+            # Ignore SystemExit which could be raised on --dry-run
+            if e.code != 0:
+                raise
+
+if __name__ == "__main__":
+    main()

src/decimate.py

@@ -0,0 +1,85 @@
+#!/usr/bin/python
+
+import nilmtools.filter
+import nilmdb.client
+import numpy as np
+import operator
+
+def main(argv = None):
+    f = nilmtools.filter.Filter()
+    parser = f.setup_parser("Decimate a stream")
+    group = parser.add_argument_group("Decimate options")
+    group.add_argument('-f', '--factor', action='store', default=4, type=int,
+                       help='Decimation factor (default: %(default)s)')
+
+    # Parse arguments
+    try:
+        args = f.parse_args(argv)
+    except nilmtools.filter.MissingDestination as e:
+        # If no destination, suggest how to create it by figuring out
+        # a recommended layout.
+        src = e.src
+        dest = e.dest
+        print "Source is %s (%s)" % (src.path, src.layout)
+        print "Destination %s doesn't exist" % (dest.path)
+        if "decimate_source" in f.client_src.stream_get_metadata(src.path):
+            rec = src.layout
+        elif 'int32' in src.layout_type or 'float64' in src.layout_type:
+            rec = 'float64_' + str(src.layout_count * 3)
+        else:
+            rec = 'float32_' + str(src.layout_count * 3)
+        print "You could make it with a command like:"
+        print "  nilmtool -u %s create %s %s" % (e.dest.url,
+                                                 e.dest.path, rec)
+        raise SystemExit(1)
+
+    if not (args.factor >= 2):
+        raise Exception("factor needs to be 2 or more")
+
+    f.check_dest_metadata({ "decimate_source": f.src.path,
+                            "decimate_factor": args.factor })
+
+    # If source is decimated, we have to decimate a bit differently
+    if "decimate_source" in f.client_src.stream_get_metadata(args.srcpath):
+        again = True
+    else:
+        again = False
+    f.process_numpy(decimate, args = (args.factor, again))
+
+def decimate(data, interval, args, insert_function, final):
+    """Decimate data"""
+    (factor, again) = args
+    (n, m) = data.shape
+
+    # Figure out which columns to use as the source for mean, min, and max,
+    # depending on whether this is the first decimation or we're decimating
+    # again.  Note that we include the timestamp in the means.
+    if again:
+        c = (m - 1) // 3
+        # e.g. c = 3
+        # ts mean1 mean2 mean3 min1 min2 min3 max1 max2 max3
+        mean_col = slice(0, c + 1)
+        min_col = slice(c + 1, 2 * c + 1)
+        max_col = slice(2 * c + 1, 3 * c + 1)
+    else:
+        mean_col = slice(0, m)
+        min_col = slice(1, m)
+        max_col = slice(1, m)
+
+    # Discard extra rows that aren't a multiple of factor
+    n = n // factor * factor
+    data = data[:n,:]
+
+    # Reshape it into 3D so we can process 'factor' rows at a time
+    data = data.reshape(n // factor, factor, m)
+
+    # Fill the result
+    out = np.c_[ np.mean(data[:,:,mean_col], axis=1),
+                 np.min(data[:,:,min_col], axis=1),
+                 np.max(data[:,:,max_col], axis=1) ]
+
+    insert_function(out)
+    return n
+
+if __name__ == "__main__":
+    main()

src/decimate_auto.py

@@ -0,0 +1,76 @@
+#!/usr/bin/python
+
+import nilmtools.filter
+import nilmtools.decimate
+import nilmdb.client
+import argparse
+
+def main(argv = None):
+    parser = argparse.ArgumentParser(
+        formatter_class = argparse.RawDescriptionHelpFormatter,
+        version = "1.0",
+        description = """\
+    Automatically create multiple decimations from a single source
+    stream, continuing until the last decimated level contains fewer
+    than 500 points total.
+    """)
+    parser.add_argument("-u", "--url", action="store",
+                        default="http://localhost/nilmdb/",
+                        help="NilmDB server URL (default: %(default)s)")
+    parser.add_argument('-f', '--factor', action='store', default=4, type=int,
+                        help='Decimation factor (default: %(default)s)')
+    parser.add_argument("--force-metadata", action="store_true",
+                        default = False,
+                        help="Force metadata changes if the dest "
+                        "doesn't match")
+    parser.add_argument("path", action="store",
+                        help='Path of base stream')
+    args = parser.parse_args(argv)
+
+    # Pull out info about the base stream
+    client = nilmdb.client.Client(args.url)
+
+    info = nilmtools.filter.get_stream_info(client, args.path)
+    if not info:
+        raise Exception("path " + args.path + " not found")
+
+    meta = client.stream_get_metadata(args.path)
+    if "decimate_source" in meta:
+        print "Stream", args.path, "was decimated from", meta["decimate_source"]
+        print "You need to pass the base stream instead"
+        raise SystemExit(1)
+
+    # Figure out the type we should use for decimated streams
+    if 'int32' in info.layout_type or 'float64' in info.layout_type:
+        decimated_type = 'float64_' + str(info.layout_count * 3)
+    else:
+        decimated_type = 'float32_' + str(info.layout_count * 3)
+
+    # Now do the decimations until we have few enough points
+    factor = 1
+    while True:
+        print "Level", factor, "decimation has", info.rows, "rows"
+        if info.rows <= 500:
+            break
+        factor *= args.factor
+        new_path = "%s~decim-%d" % (args.path, factor)
+
+        # Create the stream if needed
+        new_info = nilmtools.filter.get_stream_info(client, new_path)
+        if not new_info:
+            print "Creating stream", new_path
+            client.stream_create(new_path, decimated_type)
+
+        # Run the decimation as if it were run from the commandline
+        new_argv = [ "-u", args.url,
+                     "-f", str(args.factor) ]
+        if args.force_metadata:
+            new_argv.extend([ "--force-metadata" ])
+        new_argv.extend([info.path, new_path])
+        nilmtools.decimate.main(new_argv)
+
+        # Update info using the newly decimated stream
+        info = nilmtools.filter.get_stream_info(client, new_path)
+
+if __name__ == "__main__":
+    main()

src/filter.py

@@ -0,0 +1,334 @@
+#!/usr/bin/python
+
+from __future__ import absolute_import
+
+import nilmdb.client
+from nilmdb.client import Client
+from nilmdb.client.numpyclient import NumpyClient
+from nilmdb.utils.printf import *
+from nilmdb.utils.time import (parse_time, timestamp_to_human,
+                               timestamp_to_seconds)
+from nilmdb.utils.interval import Interval
+
+import nilmtools
+
+import itertools
+import time
+import sys
+import re
+import argparse
+import numpy as np
+import cStringIO
+
+class MissingDestination(Exception):
+    def __init__(self, args, src, dest):
+        self.parsed_args = args
+        self.src = src
+        self.dest = dest
+        Exception.__init__(self, "destination path " + dest.path + " not found")
+
+class StreamInfo(object):
+    def __init__(self, url, info):
+        self.url = url
+        self.info = info
+        try:
+            self.path = info[0]
+            self.layout = info[1]
+            self.layout_type = self.layout.split('_')[0]
+            self.layout_count = int(self.layout.split('_')[1])
+            self.total_count = self.layout_count + 1
+            self.timestamp_min = info[2]
+            self.timestamp_max = info[3]
+            self.rows = info[4]
+            self.seconds = nilmdb.utils.time.timestamp_to_seconds(info[5])
+        except IndexError, TypeError:
+            pass
+
+    def string(self, interhost):
+        """Return stream info as a string.  If interhost is true,
+        include the host URL."""
+        if interhost:
+            return sprintf("[%s] ", self.url) + str(self)
+        return str(self)
+
+    def __str__(self):
+        """Return stream info as a string."""
+        return sprintf("%s (%s), %.2fM rows, %.2f hours",
+                       self.path, self.layout, self.rows / 1e6,
+                       self.seconds / 3600.0)
+
+def get_stream_info(client, path):
+    """Return a StreamInfo object about the given path, or None if it
+    doesn't exist"""
+    streams = client.stream_list(path, extended = True)
+    if len(streams) != 1:
+        return None
+    return StreamInfo(client.geturl(), streams[0])
+
+class Filter(object):
+
+    def __init__(self):
+        self._parser = None
+        self._client_src = None
+        self._client_dest = None
+        self._using_client = False
+        self.src = None
+        self.dest = None
+        self.start = None
+        self.end = None
+        self.interhost = False
+        self.force_metadata = False
+
+    @property
+    def client_src(self):
+        if self._using_client:
+            raise Exception("Filter client is in use; make another")
+        return self._client_src
+
+    @property
+    def client_dest(self):
+        if self._using_client:
+            raise Exception("Filter client is in use; make another")
+        return self._client_dest
+
+    def setup_parser(self, description = "Filter data", skip_paths = False):
+        parser = argparse.ArgumentParser(
+            formatter_class = argparse.RawDescriptionHelpFormatter,
+            version = nilmtools.__version__,
+            description = description)
+        group = parser.add_argument_group("General filter arguments")
+        group.add_argument("-u", "--url", action="store",
+                           default="http://localhost/nilmdb/",
+                           help="Server URL (default: %(default)s)")
+        group.add_argument("-U", "--dest-url", action="store",
+                           help="Destination server URL "
+                           "(default: same as source)")
+        group.add_argument("-D", "--dry-run", action="store_true",
+                           default = False,
+                           help="Just print intervals that would be "
+                           "processed")
+        group.add_argument("--force-metadata", action="store_true",
+                           default = False,
+                           help="Force metadata changes if the dest "
+                           "doesn't match")
+        group.add_argument("-s", "--start",
+                           metavar="TIME", type=self.arg_time,
+                           help="Starting timestamp for intervals "
+                           "(free-form, inclusive)")
+        group.add_argument("-e", "--end",
+                           metavar="TIME", type=self.arg_time,
+                           help="Ending timestamp for intervals "
+                           "(free-form, noninclusive)")
+        if not skip_paths:
+            # Individual filter scripts might want to add these arguments
+            # themselves, to include multiple sources in a different order
+            # (for example).  "srcpath" and "destpath" arguments must exist,
+            # though.
+            group.add_argument("srcpath", action="store",
+                               help="Path of source stream, e.g. /foo/bar")
+            group.add_argument("destpath", action="store",
+                               help="Path of destination stream, e.g. /foo/bar")
+        self._parser = parser
+        return parser
+
+    def interval_string(self, interval):
+        return sprintf("[ %s -> %s ]",
+                       timestamp_to_human(interval.start),
+                       timestamp_to_human(interval.end))
+
+    def parse_args(self, argv = None):
+        args = self._parser.parse_args(argv)
+
+        if args.dest_url is None:
+            args.dest_url = args.url
+        if args.url != args.dest_url:
+            self.interhost = True
+
+        self._client_src = Client(args.url)
+        self._client_dest = Client(args.dest_url)
+
+        if (not self.interhost) and (args.srcpath == args.destpath):
+            self._parser.error("source and destination path must be different")
+
+        # Open and print info about the streams
+        self.src = get_stream_info(self._client_src, args.srcpath)
+        if not self.src:
+            self._parser.error("source path " + args.srcpath + " not found")
+
+        self.dest = get_stream_info(self._client_dest, args.destpath)
+        if not self.dest:
+            raise MissingDestination(args, self.src,
+                                     StreamInfo(args.dest_url, [args.destpath]))
+
+        print "Source:", self.src.string(self.interhost)
+        print "  Dest:", self.dest.string(self.interhost)
+
+        if args.dry_run:
+            for interval in self.intervals():
+                print self.interval_string(interval)
+            raise SystemExit(0)
+
+        self.force_metadata = args.force_metadata
+
+        self.start = args.start
+        self.end = args.end
+
+        return args
+
+    def _optimize_int(self, it):
+        """Join and yield adjacent intervals from the iterator 'it'"""
+        saved_int = None
+        for interval in it:
+            if saved_int is not None:
+                if saved_int.end == interval.start:
+                    interval.start = saved_int.start
+                else:
+                    yield saved_int
+            saved_int = interval
+        if saved_int is not None:
+            yield saved_int
+
+    def intervals(self):
+        """Generate all the intervals that this filter should process"""
+        self._using_client = True
+
+        if self.interhost:
+            # Do the difference ourselves
+            s_intervals = ( Interval(start, end)
+                            for (start, end) in
+                            self._client_src.stream_intervals(
+                                self.src.path,
+                                start = self.start, end = self.end) )
+            d_intervals = ( Interval(start, end)
+                            for (start, end) in
+                            self._client_dest.stream_intervals(
+                                self.dest.path,
+                                start = self.start, end = self.end) )
+            intervals = nilmdb.utils.interval.set_difference(s_intervals,
+                                                             d_intervals)
+        else:
+            # Let the server do the difference for us
+            intervals = ( Interval(start, end)
+                          for (start, end) in
+                          self._client_src.stream_intervals(
+                              self.src.path, diffpath = self.dest.path,
+                              start = self.start, end = self.end) )
+        # Optimize intervals: join intervals that are adjacent
+        for interval in self._optimize_int(intervals):
+            yield interval
+        self._using_client = False
+
+    # Misc helpers
+    def arg_time(self, toparse):
+        """Parse a time string argument"""
+        try:
+            return nilmdb.utils.time.parse_time(toparse)
+        except ValueError as e:
+            raise argparse.ArgumentTypeError(sprintf("%s \"%s\"",
+                                                     str(e), toparse))
+
+    def check_dest_metadata(self, data):
+        """See if the metadata jives, and complain if it doesn't.  If
+        there's no conflict, update the metadata to match 'data'."""
+        metadata = self._client_dest.stream_get_metadata(self.dest.path)
+        if not self.force_metadata:
+            for key in data:
+                wanted = str(data[key])
+                val = metadata.get(key, wanted)
+                if val != wanted and self.dest.rows > 0:
+                    m =  "Metadata in destination stream:\n"
+                    m += "  %s = %s\n" % (key, val)
+                    m += "doesn't match desired data:\n"
+                    m += "  %s = %s\n" % (key, wanted)
+                    m += "Refusing to change it.  To prevent this error, "
+                    m += "change or delete the metadata with nilmtool,\n"
+                    m += "remove existing data from the stream, or "
+                    m += "retry with --force-metadata."
+                    raise Exception(m)
+        # All good -- write the metadata in case it's not already there
+        self._client_dest.stream_update_metadata(self.dest.path, data)
+
+    # The main filter processing method.
+    def process_numpy(self, function, args = None, rows = 100000):
+        """For all intervals that exist in self.src but don't exist in
+        self.dest, call 'function' with a Numpy array corresponding to
+        the data.  The data is converted to a Numpy array in chunks of
+        'rows' rows at a time.
+
+        'function' should be defined as:
+           def function(data, interval, args, insert_func, final)
+
+        'data': array of data to process -- may be empty
+
+        'interval': overall interval we're processing (but not necessarily
+        the interval of this particular chunk of data)
+
+        'args': opaque arguments passed to process_numpy
+
+        'insert_func': function to call in order to insert array of data.
+        Should be passed a 2-dimensional array of data to insert.
+        Data timestamps must be within the provided interval.
+
+        'final': True if this is the last bit of data for this
+        contiguous interval, False otherwise.
+
+        Return value of 'function' is the number of data rows processed.
+        Unprocessed data will be provided again in a subsequent call
+        (unless 'final' is True).
+        """
+        if args is None:
+            args = []
+        extractor = NumpyClient(self.src.url).stream_extract_numpy
+        inserter = NumpyClient(self.dest.url).stream_insert_numpy_context
+
+        for interval in self.intervals():
+            print "Processing", self.interval_string(interval)
+            with inserter(self.dest.path,
+                          interval.start, interval.end) as insert_ctx:
+                insert_function = insert_ctx.insert
+                old_array = np.array([])
+                for new_array in extractor(self.src.path,
+                                           interval.start, interval.end,
+                                           layout = self.src.layout,
+                                           maxrows = rows):
+                    # If we still had old data left, combine it
+                    if old_array.shape[0] != 0:
+                        array = np.vstack((old_array, new_array))
+                    else:
+                        array = new_array
+
+                    # Pass it to the process function
+                    processed = function(array, interval, args,
+                                         insert_function, False)
+
+                    # Send any pending data
+                    insert_ctx.send()
+
+                    # Save the unprocessed parts
+                    if processed >= 0:
+                        old_array = array[processed:]
+                    else:
+                        raise Exception(
+                            sprintf("%s return value %s must be >= 0",
+                                    str(function), str(processed)))
+
+                    # Warn if there's too much data remaining
+                    if old_array.shape[0] > 3 * rows:
+                        printf("warning: %d unprocessed rows in buffer\n",
+                               old_array.shape[0])
+
+                # Last call for this contiguous interval
+                if old_array.shape[0] != 0:
+                    function(old_array, interval, args, insert_function, True)
+
+def main(argv = None):
+    # This is just a dummy function; actual filters can use the other
+    # functions to prepare stuff, and then do something with the data.
+    f = Filter()
+    parser = f.setup_parser()
+    args = f.parse_args(argv)
+    for i in f.intervals():
+        print "Generic filter: need to handle", f.interval_string(i)
+
+if __name__ == "__main__":
+    main()

src/insert.py

@@ -0,0 +1,268 @@
+#!/usr/bin/python
+
+import nilmdb.client
+from nilmdb.utils.printf import *
+from nilmdb.utils.time import (parse_time, timestamp_to_human,
+                               timestamp_to_seconds, seconds_to_timestamp,
+                               rate_to_period, now as time_now)
+
+import nilmtools
+import time
+import sys
+import re
+import argparse
+import subprocess
+import textwrap
+
+class ParseError(Exception):
+    def __init__(self, filename, error):
+        msg = filename + ": " + error
+        super(ParseError, self).__init__(msg)
+
+def parse_args(argv = None):
+    parser = argparse.ArgumentParser(
+        formatter_class = argparse.RawDescriptionHelpFormatter,
+        version = nilmtools.__version__,
+        description = textwrap.dedent("""\
+    Insert large amount of data from an external source like ethstream.
+
+    This code tracks two timestamps:
+
+    (1) The 'data' timestamp is the precise timestamp corresponding to
+        a particular row of data, and is the timestamp that gets
+        inserted into the database.  It increases by 'data_delta' for
+        every row of input.
+
+        'data_delta' can come from one of two sources.  If '--delta'
+        is specified, it is pulled from the first column of data.  If
+        '--rate' is specified, 'data_delta' is set to a fixed value of
+        (1 / rate).
+
+    (2) The 'clock' timestamp is the less precise timestamp that gives
+        the absolute time.  It can come from two sources.  If '--live'
+        is specified, it is pulled directly from the system clock.  If
+        '--file' is specified, it is extracted from the input filename
+        every time a new file is opened for read, and from comments
+        that appear in the file.
+
+    Small discrepencies between 'data' and 'clock' are ignored.  If
+    the 'data' timestamp ever differs from the 'clock' timestamp by
+    more than 'max_gap' seconds:
+
+    - If 'data' is running behind, there is a gap in the data, so it
+      is stepped forward to match 'clock'.
+
+    - If 'data' is running ahead, there is overlap in the data, and an
+      error is raised.
+    """))
+    parser.add_argument("-u", "--url", action="store",
+                        default="http://localhost/nilmdb/",
+                        help="NilmDB server URL (default: %(default)s)")
+    group = parser.add_argument_group("Misc options")
+    group.add_argument("-D", "--dry-run", action="store_true",
+                       help="Parse files, but don't insert any data")
+    group.add_argument("-m", "--max-gap", action="store", default=10.0,
+                       metavar="SEC", type=float,
+                       help="Max discrepency between clock and data "
+                       "timestamps (default: %(default)s)")
+
+    group = parser.add_argument_group("Data timestamp delta")
+    exc = group.add_mutually_exclusive_group()
+    exc.add_argument("-r", "--rate", action="store", default=8000.0,
+                     type=float,
+                     help="Data_delta is constant 1/RATE "
+                     "(default: %(default)s Hz)")
+    exc.add_argument("-d", "--delta", action="store_true",
+                     help="Data_delta is the first number in each line")
+
+    group = parser.add_argument_group("Clock timestamp source")
+    exc = group.add_mutually_exclusive_group()
+    exc.add_argument("-l", "--live", action="store_true",
+                     help="Use live system time for clock timestamp")
+    exc.add_argument("-f", "--file", action="store_true", default=True,
+                     help="Use filename or comments for clock timestamp")
+    group.add_argument("-o", "--offset-filename", metavar="SEC",
+                       action="store", default=-3600.0, type=float,
+                       help="Offset to add to filename timestamps "
+                       "(default: %(default)s)")
+    group.add_argument("-O", "--offset-comment", metavar="SEC",
+                       action="store", default=0.0, type=float,
+                       help="Offset to add to comment timestamps "
+                       "(default: %(default)s)")
+
+    group = parser.add_argument_group("Database path")
+    group.add_argument("path", action="store",
+                       help="Path of stream, e.g. /foo/bar")
+
+    group = parser.add_argument_group("Input files")
+    group.add_argument("infile", type=argparse.FileType('r'), nargs='*',
+                       default=[sys.stdin],
+                       help="Input files (default: stdin)")
+
+    args = parser.parse_args(argv)
+
+    printf("     Stream path: %s\n", args.path)
+
+    printf("  Data timestamp: ")
+    if args.delta:
+        printf("delta on each input line\n")
+    else:
+        printf("fixed rate %s Hz\n", repr(args.rate))
+
+    printf(" Clock timestamp: ")
+    if args.live:
+        printf("live system clock\n")
+    else:
+        printf("from filenames and comments\n")
+        printf(" Filename offset: %s seconds\n", repr(args.offset_filename))
+        printf("  Comment offset: %s seconds\n", repr(args.offset_comment))
+
+    printf("         Max gap: %s seconds\n", repr(args.max_gap))
+    if args.dry_run:
+        printf("Dry run (no data will be inserted)\n")
+
+    return args
+
+def main(argv = None):
+    args = parse_args(argv)
+
+    client = nilmdb.client.Client(args.url)
+
+    # data_ts is the timestamp that we'll use for the current line
+    data_ts_base = 0
+    data_ts_inc = 0
+    data_ts_rate = args.rate
+    data_ts_delta = 0
+    def get_data_ts():
+        if args.delta:
+            return data_ts_base + data_ts_delta
+        else:
+            return data_ts_base + rate_to_period(data_ts_rate,
+                                                 data_ts_inc)
+
+    # clock_ts is the imprecise "real" timestamp (from the filename,
+    # comments, or system clock)
+    clock_ts = None
+
+    def print_clock_updated():
+        printf("Clock timestamp updated to %s\n", timestamp_to_human(clock_ts))
+        if data_ts_base != 0:
+            diff = get_data_ts() - clock_ts
+            if diff >= 0:
+                printf("  (data timestamp ahead by %.6f sec)\n",
+                       timestamp_to_seconds(diff))
+            else:
+                printf("  (data timestamp behind by %.6f sec)\n",
+                       timestamp_to_seconds(-diff))
+
+    offset_filename = seconds_to_timestamp(args.offset_filename)
+    offset_comment = seconds_to_timestamp(args.offset_comment)
+    max_gap = seconds_to_timestamp(args.max_gap)
+
+    with client.stream_insert_context(args.path) as stream:
+        for f in args.infile:
+            filename = f.name
+            printf("Processing %s\n", filename)
+
+            # If the filename ends in .gz, re-open it with gzip to
+            # decompress.
+            if filename.endswith(".gz"):
+                p = subprocess.Popen(["gzip", "-dc"],
+                                     stdin = f, stdout = subprocess.PIPE)
+                f = p.stdout
+
+            # Try to get a real timestamp from the filename
+            try:
+                # Subtract 1 hour because files are created at the end
+                # of the hour.  Hopefully, we'll be able to use
+                # internal comments and this value won't matter anyway.
+                clock_ts = parse_time(filename) + offset_filename
+                print_clock_updated()
+            except ValueError:
+                pass
+
+            truncated_lines = 0
+
+            # Read each line
+            for line in f:
+                # Once in a while a line might be truncated, if we're
+                # at the end of a file.  Ignore it, but if we ignore
+                # too many, bail out.
+                if line[-1] != '\n':
+                    truncated_lines += 1
+                    if truncated_lines > 3:
+                        raise ParseError(filename, "too many short lines")
+                    printf("Ignoring short line in %s\n", filename)
+                    continue
+
+                # If no content other than the newline, skip it
+                if len(line) <= 1:
+                    continue
+
+                # If line starts with a comment, look for a timestamp
+                if line[0] == '#':
+                    try:
+                        clock_ts = parse_time(line[1:]) + offset_comment
+                        print_clock_updated()
+                    except ValueError:
+                        pass
+                    continue
+
+                # If --delta mode, increment data_ts_delta by the
+                # delta from the file.
+                if args.delta:
+                    try:
+                        (delta, line) = line.split(None, 1)
+                        data_ts_delta += float(delta)
+                    except ValueError:
+                        raise ParseError(filename, "can't parse delta")
+
+                # Calculate data_ts for this row
+                data_ts = get_data_ts()
+
+                # If inserting live, use clock timestamp
+                if args.live:
+                    clock_ts = time_now()
+
+                # If we have a real timestamp, compare it to the data
+                # timestamp, and make sure things match up.
+                if clock_ts is not None:
+                    if (data_ts - max_gap) > clock_ts:
+                        # Accumulated line timestamps are in the future.
+                        # If we were to set data_ts=clock_ts, we'd create
+                        # an overlap, so we have to just bail out here.
+                        err = sprintf("Data is coming in too fast: data time "
+                                      "is %s but clock time is only %s",
+                                      timestamp_to_human(data_ts),
+                                      timestamp_to_human(clock_ts))
+                        raise ParseError(filename, err)
+
+                    if (data_ts + max_gap) < clock_ts:
+                        # Accumulated line timetamps are in the past.  We
+                        # can just skip some time and leave a gap in the
+                        # data.
+                        if data_ts_base != 0:
+                            printf("Skipping data timestamp forward from "
+                                   "%s to %s to match clock time\n",
+                                   timestamp_to_human(data_ts),
+                                   timestamp_to_human(clock_ts))
+                        stream.finalize()
+                        data_ts_base = data_ts = clock_ts
+                        data_ts_inc = data_ts_delta = 0
+
+                    # Don't use this clock time anymore until we update it
+                    clock_ts = None
+
+                if data_ts_base == 0:
+                    raise ParseError(filename, "No idea what timestamp to use")
+
+                # This line is legit, so increment timestamp (for --rate)
+                data_ts_inc += 1
+
+                # Insert it
+                if not args.dry_run:
+                    stream.insert("%d %s" % (data_ts, line))
+    print "Done"
+
+if __name__ == "__main__":
+    main()

src/prep.py

@@ -0,0 +1,169 @@
+#!/usr/bin/python
+
+# Spectral envelope preprocessor.
+# Requires two streams as input: the original raw data, and sinefit data.
+
+import nilmtools.filter
+import nilmdb.client
+from numpy import *
+import scipy.fftpack
+import scipy.signal
+#from matplotlib import pyplot as p
+import bisect
+
+def main(argv = None):
+    # Set up argument parser
+    f = nilmtools.filter.Filter()
+    parser = f.setup_parser("Spectral Envelope Preprocessor", skip_paths = True)
+    group = parser.add_argument_group("Prep options")
+    group.add_argument("-c", "--column", action="store", type=int,
+                       help="Column number (first data column is 1)")
+    group.add_argument("-n", "--nharm", action="store", type=int, default=4,
+                       help="number of odd harmonics to compute (default 4)")
+    group.add_argument("-N", "--nshift", action="store", type=int, default=1,
+                       help="number of shifted FFTs per period (default 1)")
+    exc = group.add_mutually_exclusive_group()
+    exc.add_argument("-r", "--rotate", action="store", type=float,
+                     help="rotate FFT output by this many degrees (default 0)")
+    exc.add_argument("-R", "--rotate-rad", action="store", type=float,
+                     help="rotate FFT output by this many radians (default 0)")
+
+    group.add_argument("srcpath", action="store",
+                       help="Path of raw input, e.g. /foo/raw")
+    group.add_argument("sinepath", action="store",
+                       help="Path of sinefit input, e.g. /foo/sinefit")
+    group.add_argument("destpath", action="store",
+                       help="Path of prep output, e.g. /foo/prep")
+
+    # Parse arguments
+    try:
+        args = f.parse_args(argv)
+    except nilmtools.filter.MissingDestination as e:
+        rec = "float32_%d" % (e.parsed_args.nharm * 2)
+        print "Source is %s (%s)" % (e.src.path, e.src.layout)
+        print "Destination %s doesn't exist" % (e.dest.path)
+        print "You could make it with a command like:"
+        print "  nilmtool -u %s create %s %s" % (e.dest.url, e.dest.path, rec)
+        raise SystemExit(1)
+
+    if f.dest.layout_count != args.nharm * 2:
+        print "error: need", args.nharm*2, "columns in destination stream"
+        raise SystemExit(1)
+
+    # Check arguments
+    if args.column is None or args.column < 1:
+        parser.error("need a column number >= 1")
+
+    if args.nharm < 1 or args.nharm > 32:
+        parser.error("number of odd harmonics must be 1-32")
+
+    if args.nshift < 1:
+        parser.error("number of shifted FFTs must be >= 1")
+
+    if args.rotate is not None:
+        rotation = args.rotate * 2.0 * pi / 360.0
+    else:
+        rotation = args.rotate_rad or 0.0
+
+    # Check the sine fit stream
+    client_sinefit = nilmdb.client.Client(args.url)
+    sinefit = nilmtools.filter.get_stream_info(client_sinefit, args.sinepath)
+    if not sinefit:
+        raise Exception("sinefit data not found")
+    if sinefit.layout != "float32_3":
+        raise Exception("sinefit data type is " + sinefit.layout
+                        + "; expected float32_3")
+
+    # Check and set metadata in prep stream
+    f.check_dest_metadata({ "prep_raw_source": f.src.path,
+                            "prep_sinefit_source": sinefit.path,
+                            "prep_column": args.column })
+
+    # Run the processing function on all data
+    f.process_numpy(process, args = (client_sinefit, sinefit.path, args.column,
+                                     args.nharm, rotation, args.nshift))
+
+def process(data, interval, args, insert_function, final):
+    (client, sinefit_path, column, nharm, rotation, nshift) = args
+    rows = data.shape[0]
+    data_timestamps = data[:,0]
+
+    if rows < 2:
+        return 0
+
+    last_inserted = [nilmdb.utils.time.min_timestamp]
+    def insert_if_nonoverlapping(data):
+        """Call insert_function to insert data, but only if this
+        data doesn't overlap with other data that we inserted."""
+        if data[0][0] <= last_inserted[0]:
+            return
+        last_inserted[0] = data[-1][0]
+        insert_function(data)
+
+    processed = 0
+    out = zeros((1, nharm * 2 + 1))
+    # Pull out sinefit data for the entire time range of this block
+    for sinefit_line in client.stream_extract(sinefit_path,
+                                              data[0, 0], data[rows-1, 0]):
+
+        def prep_period(t_min, t_max, rot):
+            """
+            Compute prep coefficients from time t_min to t_max, which
+            are the timestamps of the start and end of one period.
+            Results are rotated by an additional extra_rot before
+            being inserted into the database.  Returns the maximum
+            index processed, or None if the period couldn't be
+            processed.
+            """
+            # Find the indices of data that correspond to (t_min, t_max)
+            idx_min = bisect.bisect_left(data_timestamps, t_min)
+            idx_max = bisect.bisect_left(data_timestamps, t_max)
+            if idx_min >= idx_max or idx_max >= len(data_timestamps):
+                return None
+
+            # Perform FFT over those indices
+            N = idx_max - idx_min
+            d = data[idx_min:idx_max, column]
+            F = scipy.fftpack.fft(d) * 2.0 / N
+
+            # If we wanted more harmonics than the FFT gave us, pad with zeros
+            if N < (nharm * 2):
+                F = r_[F, zeros(nharm * 2 - N)]
+
+            # Fill output data.
+            out[0, 0] = round(t_min)
+            for k in range(nharm):
+                Fk = F[2 * k + 1] * e**(rot * 1j * (k+1))
+                out[0, 2 * k + 1] = -imag(Fk) # Pk
+                out[0, 2 * k + 2] = real(Fk)  # Qk
+
+            insert_if_nonoverlapping(out)
+            return idx_max
+
+        # Extract sinefit data to get zero crossing timestamps.
+        # t_min = beginning of period
+        # t_max = end of period
+        (t_min, f0, A, C) = [ float(x) for x in sinefit_line.split() ]
+        t_max = t_min + 1e6 / f0
+
+        # Compute prep over shifted windows of the period
+        # (nshift is typically 1)
+        for n in range(nshift):
+            # Compute timestamps and rotations for shifted window
+            time_shift = n * (t_max - t_min) / nshift
+            shifted_min = t_min + time_shift
+            shifted_max = t_max + time_shift
+            angle_shift = n * 2 * pi / nshift
+            shifted_rot = rotation - angle_shift
+
+            # Run prep computation
+            idx_max = prep_period(shifted_min, shifted_max, shifted_rot)
+            if not idx_max:
+                break
+            processed = idx_max
+
+    print "Processed", processed, "of", rows, "rows"
+    return processed
+
+if __name__ == "__main__":
+    main()

src/sinefit.py

@@ -0,0 +1,187 @@
+#!/usr/bin/python
+
+# Sine wave fitting.  This runs about 5x faster than realtime on raw data.
+
+import nilmtools.filter
+import nilmdb.client
+from numpy import *
+from scipy import *
+#import pylab as p
+import operator
+
+def main(argv = None):
+    f = nilmtools.filter.Filter()
+    parser = f.setup_parser("Sine wave fitting")
+    group = parser.add_argument_group("Sine fit options")
+    group.add_argument('-c', '--column', action='store', type=int,
+                       help='Column number (first data column is 1)')
+    group.add_argument('-f', '--frequency', action='store', type=float,
+                       default=60.0,
+                       help='Approximate frequency (default: %(default)s)')
+
+    # Parse arguments
+    try:
+        args = f.parse_args(argv)
+    except nilmtools.filter.MissingDestination as e:
+        rec = "float32_3"
+        print "Source is %s (%s)" % (e.src.path, e.src.layout)
+        print "Destination %s doesn't exist" % (e.dest.path)
+        print "You could make it with a command like:"
+        print "  nilmtool -u %s create %s %s" % (e.dest.url, e.dest.path, rec)
+        raise SystemExit(1)
+
+    if args.column is None or args.column < 1:
+        parser.error("need a column number >= 1")
+    if args.frequency < 0.1:
+        parser.error("frequency must be >= 0.1")
+
+    f.check_dest_metadata({ "sinefit_source": f.src.path,
+                            "sinefit_column": args.column })
+    f.process_numpy(process, args = (args.column, args.frequency))
+
+def process(data, interval, args, insert_function, final):
+    (column, f_expected) = args
+    rows = data.shape[0]
+
+    # Estimate sampling frequency from timestamps
+    fs = 1e6 * (rows-1) / (data[-1][0] - data[0][0])
+
+    # Pull out about 3.5 periods of data at once;
+    # we'll expect to match 3 zero crossings in each window
+    N = max(int(3.5 * fs / f_expected), 10)
+
+    # If we don't have enough data, don't bother processing it
+    if rows < N:
+        return 0
+
+    # Process overlapping windows
+    start = 0
+    num_zc = 0
+    while start < (rows - N):
+        this = data[start:start+N, column]
+        t_min = data[start, 0]/1e6
+        t_max = data[start+N-1, 0]/1e6
+
+        # Do 4-parameter sine wave fit
+        (A, f0, phi, C) = sfit4(this, fs)
+
+        # Check bounds.  If frequency is too crazy, ignore this window
+        if f0 < (f_expected/2) or f0 > (f_expected*2):
+            print "frequency", f0, "too far from expected value", f_expected
+            start += N
+            continue
+
+        #p.plot(arange(N), this)
+        #p.plot(arange(N), A * cos(f0/fs * 2 * pi * arange(N) + phi) + C, 'g')
+
+        # Period starts when the argument of cosine is 3*pi/2 degrees,
+        # so we're looking for sample number:
+        #     n = (3 * pi / 2 - phi) / (f0/fs * 2 * pi)
+        zc_n = (3 * pi / 2 - phi) / (f0 / fs * 2 * pi)
+        period_n = fs/f0
+
+        # Add periods to make N positive
+        while zc_n < 0:
+            zc_n += period_n
+
+        last_zc = None
+        # Mark the zero crossings until we're a half period away
+        # from the end of the window
+        while zc_n < (N - period_n/2):
+            #p.plot(zc_n, C, 'ro')
+            t = t_min + zc_n / fs
+            insert_function([[t * 1e6, f0, A, C]])
+            num_zc += 1
+            last_zc = zc_n
+            zc_n += period_n
+
+        # Advance the window one quarter period past the last marked
+        # zero crossing, or advance the window by half its size if we
+        # didn't mark any.
+        if last_zc is not None:
+            advance = min(last_zc + period_n/4, N)
+        else:
+            advance = N/2
+        #p.plot(advance, C, 'go')
+        #p.show()
+
+        start = int(round(start + advance))
+
+    # Return the number of rows we've processed
+    print "Marked", num_zc, "zero-crossings in", start, "rows"
+    return start
+
+def sfit4(data, fs):
+    """(A, f0, phi, C) = sfit4(data, fs)
+
+    Compute 4-parameter (unknown-frequency) least-squares fit to
+    sine-wave data, according to IEEE Std 1241-2010 Annex B
+
+    Input:
+      data  vector of input samples
+      fs    sampling rate (Hz)
+
+    Output:
+      Parameters [A, f0,  phi, C] to fit the equation
+        x[n] = A * cos(f0/fs * 2 * pi * n + phi) + C
+      where n is sample number.  Or, as a function of time:
+        x(t) = A * cos(f0 * 2 * pi * t + phi) + C
+
+    by Jim Paris
+    (Verified to match sfit4.m)
+    """
+    N = len(data)
+    t = linspace(0, (N-1) / fs, N)
+
+    ## Estimate frequency using FFT (step b)
+    Fc = fft(data)
+    F = abs(Fc)
+    F[0] = 0   # eliminate DC
+
+    # Find pair of spectral lines with largest amplitude:
+    # resulting values are in F(i) and F(i+1)
+    i = argmax(F[0:int(N/2)] + F[1:int(N/2+1)])
+
+    # Interpolate FFT to get a better result (from Markus [B37])
+    U1 = real(Fc[i])
+    U2 = real(Fc[i+1])
+    V1 = imag(Fc[i])
+    V2 = imag(Fc[i+1])
+    n = 2 * pi / N
+    ni1 = n * i
+    ni2 = n * (i+1)
+    K = ((V2-V1)*sin(ni1) + (U2-U1)*cos(ni1)) / (U2-U1)
+    Z1 = V1 * (K - cos(ni1)) / sin(ni1) + U1
+    Z2 = V2 * (K - cos(ni2)) / sin(ni2) + U2
+    i = arccos((Z2*cos(ni2) - Z1*cos(ni1)) / (Z2-Z1)) / n
+
+    # Convert to Hz
+    f0 = i * fs / N
+
+    ## Fit it
+    # first guess for A0, B0 using 3-parameter fit (step c)
+    w = 2*pi*f0
+    D = c_[cos(w*t), sin(w*t), ones(N)]
+    s = linalg.lstsq(D, data)[0]
+
+    # Now iterate 6 times (step i)
+    for idx in range(6):
+        D = c_[cos(w*t), sin(w*t), ones(N),
+              -s[0] * t * sin(w*t) + s[1] * t * cos(w*t) ] # eqn B.16
+        s = linalg.lstsq(D, data)[0] # eqn B.18
+        w = w + s[3]	# update frequency estimate
+
+    ## Extract results
+    A = sqrt(s[0]*s[0] + s[1]*s[1]) # eqn B.21
+    f0 = w / (2*pi)
+    try:
+        phi = -arctan2(s[1], s[0]) # eqn B.22
+    except TypeError:
+        # something broke down, just return zeros
+        return (0, 0, 0, 0)
+    C = s[2]
+
+    return (A, f0, phi, C)
+
+if __name__ == "__main__":
+    main()