def test_tbf_read(self):
"""Test reading in a frame from a TBF file."""
fh = open(tbfFile, 'rb')
# First frame is really TBF and stores the first channel
frame1 = tbf.read_frame(fh)
self.assertTrue(frame1.header.is_tbf)
self.assertEqual(frame1.header.first_chan, 2348)
# Second frame
frame2 = tbf.read_frame(fh)
self.assertTrue(frame2.header.is_tbf)
self.assertEqual(frame2.header.first_chan, 2360)
fh.close()
def test_tbf_buffer_flush(self):
"""Test the TBF ring buffer's flush() function."""
fh = open(tbfFile, 'rb')
nFpO = tbf.get_frames_per_obs(fh)
# Create the FrameBuffer instance
frameBuffer = buffer.TBFFrameBuffer(
chans=[2348, 2360, 2372, 2384, 2396])
# Go
while True:
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
continue
frameBuffer.append(cFrame)
cFrames = frameBuffer.get()
if cFrames is None:
continue
fh.close()
# Flush the buffer
for cFrames in frameBuffer.flush():
# Make sure the dump has one of the expected time tags
self.assertTrue(
cFrames[0].payload.timetag in (283685766952000000, ))
# Make sure it has the right number of frames
self.assertEqual(len(cFrames), nFpO)
def test_tbf_math(self):
"""Test mathematical operations on TBF frame data via frames."""
fh = open(tbfFile, 'rb')
# Frames 1 through 3
frames = []
for i in range(1, 4):
frames.append(tbf.read_frame(fh))
fh.close()
# Multiplication
frameT = frames[0] * 2.0
for i in range(12 * 256 * 2):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(frameT.payload.data[c, s, p],
2 * frames[0].payload.data[c, s, p], 2)
frameT *= 2.0
for i in range(12 * 256 * 2):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(frameT.payload.data[c, s, p],
4 * frames[0].payload.data[c, s, p], 2)
frameT = frames[0] * frames[1]
for i in range(12 * 256 * 2):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(
frameT.payload.data[c, s, p], frames[0].payload.data[c, s, p] *
frames[1].payload.data[c, s, p], 2)
# Addition
frameA = frames[0] + 2.0
for i in range(800):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(frameA.payload.data[c, s, p],
2 + frames[0].payload.data[c, s, p], 2)
frameA += 2.0
for i in range(800):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(frameA.payload.data[c, s, p],
4 + frames[0].payload.data[c, s, p], 2)
frameA = frames[0] + frames[1]
for i in range(800):
c = i // 2 // 256
s = i // 2 % 256
p = i % 2
self.assertAlmostEqual(
frameA.payload.data[c, s, p], frames[0].payload.data[c, s, p] +
frames[1].payload.data[c, s, p], 2)
def test_tbf_sort(self):
"""Test sorting TBF frames by time tags."""
fh = open(tbfFile, 'rb')
# Frames 1 through 3
frames = []
for i in range(1, 4):
frames.append(tbf.read_frame(fh))
fh.close()
frames.sort()
frames = frames[::-1]
for i in range(1, len(frames)):
self.assertTrue(frames[i - 1] >= frames[i])
def test_tbf_comps(self):
"""Test the TBF frame comparison operators (>, <, etc.) for time tags."""
fh = open(tbfFile, 'rb')
# Frames 1 through 4
frames = []
for i in range(1, 5):
frames.append(tbf.read_frame(fh))
fh.close()
self.assertTrue(0 < frames[0])
self.assertFalse(0 > frames[0])
self.assertTrue(frames[-1] >= frames[0])
self.assertTrue(frames[-1] <= frames[0])
self.assertTrue(frames[0] == frames[0])
self.assertTrue(frames[0] == frames[-1])
self.assertFalse(frames[0] != frames[0])
def test_tbf_default(self):
"""Test the TBF ring buffer with the default values."""
fh = open(tbfFile, 'rb')
nFpO = tbf.get_frames_per_obs(fh)
# Create the FrameBuffer instance
frameBuffer = buffer.TBFFrameBuffer(
chans=[2348, 2360, 2372, 2384, 2396])
# Go
while True:
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
continue
frameBuffer.append(cFrame)
cFrames = frameBuffer.get()
if cFrames is None:
continue
fh.close()
# Make sure we have the right number of frames in the buffer
nFrames = 0
for key in frameBuffer.buffer.keys():
nFrames = nFrames + len(frameBuffer.buffer[key])
self.assertEqual(nFrames, 5)
# Make sure nothing has happened that shouldn't have
self.assertEqual(frameBuffer.full, 0)
self.assertEqual(frameBuffer.partial, 0)
self.assertEqual(frameBuffer.missing, 0)
self.assertEqual(frameBuffer.dropped, 0)
# Make sure we have the right keys
for key in frameBuffer.buffer.keys():
self.assertTrue(key in (283685766952000000, ))
# Make sure the buffer keys have the right sizes
self.assertEqual(len(frameBuffer.buffer[283685766952000000]), 5)
def test_tbf_errors(self):
"""Test TBF reading errors."""
fh = open(tbfFile, 'rb')
# Frames 1 through 5
for i in range(1, 6):
frame = tbf.read_frame(fh)
# Last frame should be an error (errors.EOFError)
self.assertRaises(errors.EOFError, tbf.read_frame, fh)
fh.close()
# If we offset in the file by 1 byte, we should be a
# sync error (errors.SyncError).
fh = open(tbfFile, 'rb')
fh.seek(1)
self.assertRaises(errors.SyncError, tbf.read_frame, fh)
fh.close()
def test_tbf_buffer_reorder(self):
"""Test the reorder function of the TBF ring buffer."""
fh = open(tbfFile, 'rb')
nFpO = tbf.get_frames_per_obs(fh)
# Create the FrameBuffer instance
frameBuffer = buffer.TBFFrameBuffer(
chans=[2348, 2360, 2372, 2384, 2396], reorder=True)
# Go
while True:
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
continue
frameBuffer.append(cFrame)
cFrames = frameBuffer.get()
if cFrames is None:
continue
# Make sure the dump has one of the expected time tags
self.assertTrue(
cFrames[0].payload.timetag in (283685766952000000, ))
# Make sure it has the right number of frames
self.assertEqual(len(cFrames), nFpO)
# Check the order
for i in range(1, len(cFrames)):
pC = cFrames[i - 1].header.first_chan
cC = cFrames[i].header.first_chan
self.assertTrue(cC > pC)
fh.close()
def test_tbf_math(self):
"""Test mathematical operations on TBF frame data via frames."""
fh = open(tbfFile, 'rb')
# Frames 1 through 3
frames = []
for i in range(1, 4):
frames.append(tbf.read_frame(fh))
fh.close()
# Multiplication
frameT = frames[0] * 2.0
numpy.testing.assert_allclose(frameT.payload.data,
2 * frames[0].payload.data,
atol=1e-6)
frameT *= 2.0
numpy.testing.assert_allclose(frameT.payload.data,
4 * frames[0].payload.data,
atol=1e-6)
frameT = frames[0] * frames[1]
numpy.testing.assert_allclose(frameT.payload.data,
frames[0].payload.data *
frames[1].payload.data,
atol=1e-6)
# Addition
frameA = frames[0] + 2.0
numpy.testing.assert_allclose(frameA.payload.data,
2 + frames[0].payload.data,
atol=1e-6)
frameA += 2.0
numpy.testing.assert_allclose(frameA.payload.data,
4 + frames[0].payload.data,
atol=1e-6)
frameA = frames[0] + frames[1]
numpy.testing.assert_allclose(frameA.payload.data,
frames[0].payload.data +
frames[1].payload.data,
atol=1e-6)
def main(args):
# Setup the LWA station information
if args.metadata is not None:
try:
station = stations.parse_ssmif(args.metadata)
except ValueError:
station = metabundleADP.get_station(args.metadata, apply_sdm=True)
else:
station = stations.lwasv
antennas = station.antennas
fh = open(args.filename, 'rb')
nFrames = os.path.getsize(args.filename) / tbf.FRAME_SIZE
antpols = len(antennas)
# Read in the first frame and get the date/time of the first sample
# of the frame. This is needed to get the list of stands.
junkFrame = tbf.read_frame(fh)
fh.seek(0)
beginDate = junkFrame.time.datetime
# Figure out how many frames there are per observation and the number of
# channels that are in the file
nFramesPerObs = tbf.get_frames_per_obs(fh)
nchannels = tbf.get_channel_count(fh)
nSamples = 7840
# Figure out how many chunks we need to work with
nChunks = nFrames / nFramesPerObs
# Pre-load the channel mapper
mapper = []
for i in range(2*nFramesPerObs):
cFrame = tbf.read_frame(fh)
if cFrame.header.first_chan not in mapper:
mapper.append( cFrame.header.first_chan )
fh.seek(-2*nFramesPerObs*tbf.FRAME_SIZE, 1)
mapper.sort()
# Calculate the frequencies
freq = numpy.zeros(nchannels)
for i,c in enumerate(mapper):
freq[i*12:i*12+12] = c + numpy.arange(12)
freq *= 25e3
# File summary
print("Filename: %s" % args.filename)
print("Date of First Frame: %s" % str(beginDate))
print("Frames per Observation: %i" % nFramesPerObs)
print("Channel Count: %i" % nchannels)
print("Frames: %i" % nFrames)
print("===")
print("Chunks: %i" % nChunks)
spec = numpy.zeros((nchannels,256,2))
norm = numpy.zeros_like(spec)
for i in range(nChunks):
# Inner loop that actually reads the frames into the data array
for j in range(nFramesPerObs):
# Read in the next frame and anticipate any problems that could occur
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
print("WARNING: Mark 5C sync error on frame #%i" % (int(fh.tell())/tbf.FRAME_SIZE-1))
continue
if not cFrame.header.is_tbf:
continue
first_chan = cFrame.header.first_chan
# Figure out where to map the channel sequence to
try:
aStand = mapper.index(first_chan)
except ValueError:
mapper.append(first_chan)
aStand = mapper.index(first_chan)
# Actually load the data.
spec[aStand*12:aStand*12+12,:,:] += numpy.abs(cFrame.payload.data)**2
norm[aStand*12:aStand*12+12,:,:] += 1
spec /= norm
fh.close()
# Reshape and transpose to get it in to a "normal" order
spec.shape = (spec.shape[0], spec.shape[1]*spec.shape[2])
spec = spec.T
# Apply the cable loss corrections, if requested
if False:
for s in range(spec.shape[0]):
currGain = antennas[s].cable.gain(freq)
spec[s,:] /= currGain
# Put the frequencies in the best units possible
freq, units = _best_freq_units(freq)
# Deal with the `keep` options
if args.keep == 'all':
antpolsDisp = int(numpy.ceil(antpols/20))
js = [i for i in range(antpols)]
else:
antpolsDisp = int(numpy.ceil(len(args.keep)*2/20))
if antpolsDisp < 1:
antpolsDisp = 1
js = []
for k in args.keep:
for i,ant in enumerate(antennas):
if ant.stand.id == k:
js.append(i)
nPlot = len(js)
if nPlot < 16:
if nPlot % 4 == 0 and nPlot != 4:
figsY = 4
else:
figsY = 2
figsX = int(numpy.ceil(1.0*nPlot/figsY))
else:
figsY = 4
figsX = 4
figsN = figsX*figsY
for i in range(antpolsDisp):
# Normal plotting
fig = plt.figure()
for k in range(i*figsN, i*figsN+figsN):
try:
j = js[k]
currSpectra = numpy.squeeze( numpy.log10(spec[j,:])*10.0 )
except IndexError:
break
ax = fig.add_subplot(figsX, figsY, (k%figsN)+1)
ax.plot(freq, currSpectra, label='Stand: %i, Pol: %i (Dig: %i)' % (antennas[j].stand.id, antennas[j].pol, antennas[j].digitizer))
ax.set_title('Stand: %i (%i); Dig: %i [%i]' % (antennas[j].stand.id, antennas[j].pol, antennas[j].digitizer, antennas[j].combined_status))
ax.set_xlabel('Frequency [%s]' % units)
ax.set_ylabel('P.S.D. [dB/RBW]')
ax.set_ylim([-10, 30])
# Save spectra image if requested
if args.output is not None:
base, ext = os.path.splitext(args.output)
outFigure = "%s-%02i%s" % (base, i+1, ext)
fig.savefig(outFigure)
plt.draw()
print("RBW: %.4f %s" % ((freq[1]-freq[0]), units))
plt.show()
def main(args):
# Set the station
if args.metadata is not None:
station = stations.parse_ssmif(args.metadata)
ssmifContents = open(args.metadata).readlines()
else:
station = stations.lwasv
ssmifContents = open(os.path.join(dataPath, 'lwa1-ssmif.txt')).readlines()
antennas = station.antennas
antpols = len(antennas)
fh = open(args.filename, "rb")
nFrames = os.path.getsize(args.filename) / tbf.FRAME_SIZE
# Read in the first frame and get the date/time of the first sample
# of the frame. This is needed to get the list of stands.
junkFrame = tbf.read_frame(fh)
fh.seek(0)
beginTime = junkFrame.time
beginDate = junkFrame.time.datetime
# Figure out how many frames there are per observation and the number of
# channels that are in the file
nFramesPerObs = tbf.get_frames_per_obs(fh)
nchannels = tbf.get_channel_count(fh)
# Figure out how many chunks we need to work with
nChunks = nFrames / nFramesPerObs
# Pre-load the channel mapper
mapper = []
freq = []
for i in xrange(2*nFramesPerObs):
cFrame = tbf.read_frame(fh)
mapper.append( cFrame.header.first_chan )
freq.extend( list(cFrame.header.channel_freqs) )
fh.seek(-2*nFramesPerObs*tbf.FRAME_SIZE, 1)
mapper.sort()
freq.sort()
# File summary
print("Filename: %s" % args.filename)
print("Date of First Frame: %s" % str(beginDate))
print("Frames per Observation: %i" % nFramesPerObs)
print("Channel Count: %i" % nchannels)
print("Frames: %i" % nFrames)
print("===")
print("Chunks: %i" % nChunks)
outfile = os.path.split(args.filename)[1]
outfile = os.path.splitext(outfile)[0]
outfile = "%s.npz" % outfile
if (not os.path.exists(outfile)) or args.force:
# Master loop over all of the file chunks
masterSpectra = numpy.zeros((nChunks, 512, nchannels), numpy.float32)
for i in range(nChunks):
# Inner loop that actually reads the frames into the data array
for j in range(nFramesPerObs):
# Read in the next frame and anticipate any problems that could occur
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
print("WARNING: Mark 5C sync error on frame #%i" % (int(fh.tell())/tbf.FRAME_SIZE-1))
continue
if not cFrame.header.is_tbf:
continue
aStand = mapper.index(cFrame.header.first_chan)
# In the current configuration, stands start at 1 and go up to 10. So, we
# can use this little trick to populate the data array
if cFrame.header.frame_count % 10000 == 0 and args.verbose:
print("%4i -> %3i %6.3f %5i %i" % (cFrame.header.first_chan, aStand, cFrame.time, cFrame.header.frame_count, cFrame.payload.timetag))
# Actually load the data. x pol goes into the even numbers, y pol into the
# odd numbers
if i == 0 and j == 0:
refCount = cFrame.header.frame_count
count = cFrame.header.frame_count - refCount
masterSpectra[count,0::2,aStand*12:(aStand+1)*12] = numpy.abs( numpy.rollaxis(cFrame.payload.data[:,:,0], 1) )**2
masterSpectra[count,1::2,aStand*12:(aStand+1)*12] = numpy.abs( numpy.rollaxis(cFrame.payload.data[:,:,1], 1) )**2
# Compute the 1 ms average power and the data range within each 1 ms window
subSize = 1960
nsegments = masterSpectra.shape[1] / subSize
print("Computing average power and data range in %i-sample intervals, ADC histogram" % subSize)
pb = ProgressBar(max=masterSpectra.shape[0])
avgPower = numpy.zeros((antpols, nsegments), dtype=numpy.float32)
dataRange = numpy.zeros((antpols, nsegments, 3), dtype=numpy.int16)
adcHistogram = numpy.zeros((antpols, 4096), dtype=numpy.int32)
histBins = range(-2048, 2049)
# Apply the cable loss corrections, if requested
if True:
for s in xrange(masterSpectra.shape[1]):
currGain = antennas[s].cable.gain(freq)
for c in xrange(masterSpectra.shape[0]):
masterSpectra[c,s,:] /= currGain
# Now that we have read through all of the chunks, perform the final averaging by
# dividing by all of the chunks
spec = masterSpectra.mean(axis=0)
# Estimate the dipole resonance frequencies
print("Computing dipole resonance frequencies")
pb = ProgressBar(max=spec.shape[0])
resFreq = numpy.zeros(spec.shape[0])
toCompare = numpy.where( (freq>31e6) & (freq<70e6) )[0]
for i in xrange(spec.shape[0]):
bestOrder = 0
bestRMS = 1e34
for j in xrange(3, 12):
coeff = numpy.polyfit(freq[toCompare]/1e6, numpy.log10(spec[i,toCompare])*10, j)
fit = numpy.polyval(coeff, freq[toCompare]/1e6)
rms = ((fit - numpy.log10(spec[i,toCompare])*10)**2).sum()
if rms < bestRMS:
bestOrder = j
bestRMS = rms
coeff = numpy.polyfit(freq[toCompare]/1e6, numpy.log10(spec[i,toCompare])*10, bestOrder)
fit = numpy.polyval(coeff, freq[toCompare]/1e6)
try:
resFreq[i] = freq[toCompare[numpy.where( fit == fit.max() )[0][0]]] / 1e6
except:
pass
pb.inc(amount=1)
if pb.amount != 0 and pb.amount % 10 == 0:
sys.stdout.write(pb.show()+'\r')
sys.stdout.flush()
sys.stdout.write(pb.show()+'\r')
sys.stdout.write('\n')
sys.stdout.flush()
numpy.savez(outfile, date=str(beginDate), freq=freq, masterSpectra=masterSpectra, resFreq=resFreq,
avgPower=avgPower, dataRange=dataRange, adcHistogram=adcHistogram, ssmifContents=ssmifContents)
else:
dataDict = numpy.load(outfile)
freq = dataDict['freq']
masterSpectra = dataDict['masterSpectra']
resFreq = dataDict['resFreq']
# Now that we have read through all of the chunks, perform the final averaging by
# dividing by all of the chunks
spec = masterSpectra.mean(axis=0)
# Create a good template spectra
specTemplate = numpy.median(spec, axis=0)
specDiff = numpy.zeros(spec.shape[0])
toCompare = numpy.where( (freq>32e6) & (freq<50e6) )[0]
print(len(toCompare))
for i in xrange(spec.shape[0]):
specDiff[i] = (spec[i,toCompare] / specTemplate[toCompare]).mean()
specDiff = numpy.where( specDiff < 2, specDiff, 2)
# Get the station
standPos = numpy.array([[ant.stand.x, ant.stand.y, ant.stand.z] for ant in antennas if ant.pol == 0])
# Plots
if args.verbose:
fig = plt.figure()
ax1 = fig.add_subplot(1, 2, 1)
ax1.scatter(standPos[:,0], standPos[:,1], c=specDiff[0::2], s=40.0, alpha=0.50)
## Set the limits to just zoom in on the main stations
ax1.set_xlim([-65, 65])
ax1.set_ylim([-65, 65])
ax2 = fig.add_subplot(1, 2, 2)
ax2.plot(freq/1e6, numpy.log10(specTemplate)*10, alpha=0.50)
print("RBW: %.1f Hz" % (freq[1]-freq[0]))
plt.show()
def main(args):
fh = open(args.filename, "rb")
nFrames = os.path.getsize(args.filename) / tbf.FRAME_SIZE
# Read in the first frame and get the date/time of the first sample
# of the frame. This is needed to get the list of stands.
junkFrame = tbf.read_frame(fh)
fh.seek(0)
beginDate = junkFrame.time.datetime
# Figure out how many frames there are per observation and the number of
# channels that are in the file
nFramesPerObs = tbf.get_frames_per_obs(fh)
nchannels = tbf.get_channel_count(fh)
nSamples = 7840
# Figure out how many chunks we need to work with
nChunks = nFrames / nFramesPerObs
# Pre-load the channel mapper
mapper = []
for i in xrange(2 * nFramesPerObs):
cFrame = tbf.read_frame(fh)
if cFrame.header.first_chan not in mapper:
mapper.append(cFrame.header.first_chan)
fh.seek(-2 * nFramesPerObs * tbf.FRAME_SIZE, 1)
mapper.sort()
# File summary
print("Filename: %s" % args.filename)
print("Date of First Frame: %s" % str(beginDate))
print("Frames per Observation: %i" % nFramesPerObs)
print("Channel Count: %i" % nchannels)
print("Frames: %i" % nFrames)
print("===")
print("Chunks: %i" % nChunks)
# Master loop over all of the file chunks
timetags = numpy.zeros((nFramesPerObs, nChunks), dtype=numpy.int64) - 1
for i in xrange(nChunks):
# Inner loop that actually reads the frames into the data array
for j in xrange(nFramesPerObs):
# Read in the next frame and anticipate any problems that could occur
try:
cFrame = tbf.read_frame(fh)
except errors.EOFError:
break
except errors.SyncError:
print("WARNING: Mark 5C sync error on frame #%i" %
(int(fh.tell()) / tbf.FRAME_SIZE - 1))
continue
if not cFrame.header.is_tbf:
continue
first_chan = cFrame.header.first_chan
# Figure out where to map the channel sequence to
try:
aStand = mapper.index(first_chan)
except ValueError:
mapper.append(first_chan)
aStand = mapper.index(first_chan)
if cFrame.header.frame_count % 10000 == 0:
print("%4i -> %4i %7i %i" %
(first_chan, aStand, cFrame.header.frame_count,
cFrame.payload.timetag))
# Actually load the data. x pol goes into the even numbers, y pol into the
# odd numbers
if i == 0 and j == 0:
refCount = cFrame.header.frame_count
count = cFrame.header.frame_count - refCount
timetags[aStand, count] = cFrame.payload.timetag
# Check for missing frames
missing = numpy.where(timetags < 0)
if len(missing) != 0:
print("Found %i missing frames. Missing data from:" % len(missing[0]))
for i, f in zip(missing[0], missing[1]):
print(" channel set %4i @ frame %5i" % (mapper[i], f + 1))
# Check time tags to make sure every ant/pol as the same time as each frame
for f in xrange(timetags.shape[1]):
## For each frame count value, get the median time tag and use this for comparison.
## If things are really bad, we will get a lot of errors.
frameTime = numpy.median(timetags[:, f])
## Compare all of the antpols at a particular frame count, ignoring the ones that
## are missing.
missing = numpy.where((timetags[:, f] != frameTime)
& (timetags[:, f] >= 0))[0]
## Report any errors
for m in missing:
print("ERROR: t.t. %i @ frame %i != frame median of %i" %
(timetags[m, f], f + 1, frameTime))
print(" -> difference: %i" % (timetags[m, f] - frameTime, ))
# Check time tags to make sure the times increment correctly between frames
for i in xrange(timetags.shape[0]):
for f in xrange(1, timetags.shape[1]):
## Skip missing frames since they always fail
if timetags[i, f] < 0 or timetags[i, f - 1] < 0:
continue
## Compare the current time tag with previous and report an error if there
## is a discrepancy between the two modulo the expected skip.
if timetags[i, f] > (timetags[i, f - 1] + nSamples):
## Too far into the future
print("ERROR: t.t. %i @ frame %i > t.t. %i @ frame %i + skip" %
(timetags[i, f], f + 1, timetags[i, f - 1], f))
print(" -> difference: %i" %
(timetags[i, f] - timetags[i, f - 1], ))
elif timetags[i, f] < (timetags[i, f - 1] + nSamples):
## Not far enough into the future
print("ERROR: t.t. %i @ frame %i < t.t. %i @ frame %i + skip" %
(timetags[i, f], f + 1, timetags[i, f - 1], f))
print(" -> difference: %i" %
(timetags[i, f] - timetags[i, f - 1], ))
else:
## Everything is good if we make it here
pass
