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Proper window advancement & insertion for sine fit; comment out plots

tags/nilmtools-1.0
Jim Paris 8 years ago
parent
commit
bdfc29887b
1 changed files with 33 additions and 15 deletions
  1. +33
    -15
      src/sinefit.py

+ 33
- 15
src/sinefit.py View File

@@ -4,7 +4,7 @@ import nilmtools.filter
import nilmdb.client
from numpy import *
from scipy import *
import pylab as p
#import pylab as p
import operator

def main():
@@ -44,15 +44,17 @@ def process(data, interval, args, insert_function, final):
# Estimate sampling frequency from timestamps
fs = 1e6 * (rows-1) / (data[-1][0] - data[0][0])

# Pull out about 4 periods of data at once
N = int(4 * fs / f_expected)
# 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 chunks
# Process overlapping windows
start = 0
num_zc = 0
while start < (rows - N):
this = data[start:start+N, column]
t_min = data[start, 0]/1e6
@@ -61,34 +63,50 @@ def process(data, interval, args, insert_function, final):
# Do 4-parameter sine wave fit
(A, f0, phi, C) = sfit4(this, fs)

# Check bounds. If frequency is too crazy, ignore it
# 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), 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:
# f0/fs * 2 * pi * n + phi = 3 * pi / 2
# f0/fs * 2 * pi * n = (3 * pi / 2 - phi)
# 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.
# from the end of the window
while zc_n < (N - period_n/2):
p.plot(zc_n, C, 'ro')
#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
p.plot(zc_n, C, 'bo')
p.plot(min(N,zc_n + period_n/2), C, 'go')

p.show()
start += min(N, round(zc_n + period_n/2))
# 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))

print "processed",start,"rows"
# Return the number of rows we've processed
print "Marked", num_zc, "zero-crossings in", start, "rows"
return start

def sfit4(data, fs):


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