--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/read_trace.py Mon Dec 10 20:05:39 2007 +0100
@@ -0,0 +1,294 @@
+# -*- coding: utf-8 -*-
+
+import struct
+
+
+def decode_float(s):
+ assert len(s) in [4,8]
+ # exponential term
+ e = ord(s[-1])
+ if e & 0x80:
+ e = e - 256
+
+ # mantissa
+ m = [ord(x) for x in s[:-1]]
+ M = 0.
+ for i in range(len(s)-1):
+ #M += m[i]<<(i*8)
+ M += float(m[i])/2**((i+1)*8)
+
+ #if m[0] & 0x80:
+ # M = M - 2^(len(s))
+
+ return M * 2**(e+1)
+ mm = str(M)
+
+ mm = '0.'+mm + 'e' + str(e)
+ if len(s) == 8:
+ print "mm = ", mm
+ return eval(mm)
+
+def decode_string(s):
+ nb = ord(s[0])
+ s = s[1:nb+2]
+ r = ""
+ for c in s:
+ if ord(c)>128:
+ c = chr(ord(c)-128)
+ r += c
+ return r
+
+EDSP = {0: "No data",
+ 1: "Frequency response",
+ 2: "Power spectrum 1",
+ 3: "Power spectrum 2",
+ 4: "Coherence",
+ 5: "Cross spectrum",
+ 6: "Input time 1",
+ 7: "Input time 2",
+ 8: "Input linear spectrum 1",
+ 9: "Input linear spectrum 2",
+ 10: "Impulse response",
+ 11: "Cross correlation",
+ 12: "Auto correlation 1",
+ 13: "Auto correlation 2",
+ 14: "Histogram 1",
+ 15: "Histogram 2",
+ 16: "Cumulative density function 1",
+ 17: "Cumulative density function 2",
+ 18: "Probability density function 1",
+ 19: "Probability density function 2",
+ 20: "Average linear spectrum 1",
+ 21: "Average linear spectrum 2",
+ 22: "Average time record 1",
+ 23: "Average time record 2",
+ 24: "Synthesis pole-zeros",
+ 25: "Synthesis pole-residue",
+ 26: "Synthesis polynomial",
+ 27: "Synthesis constant",
+ 28: "Windowed time record 1",
+ 29: "Windowed time record 2",
+ 30: "Windowed linear spectrum 1",
+ 31: "Windowed linear spectrum 2",
+ 32: "Filtered time record 1",
+ 33: "Filtered time record 2",
+ 34: "Filtered linear spectrum 1",
+ 35: "Filtered linear spectrum 2",
+ 36: "Time capture buffer",
+ 37: "Captured linear spectrum",
+ 38: "Captured time record",
+ 39: "Throughput time record 1",
+ 40: "Throughput time record 2",
+ 41: "Curve fit",
+ 42: "Weighted function",
+ 43: "Not used",
+ 44: "Orbits",
+ 45: "Demodulation polar",
+ 46: "Preview demod record 1",
+ 47: "Preview demod record 2",
+ 48: "Preview demod linear spectrum 1",
+ 49: "Preview demod linear spectrum 2",
+ }
+
+ECH = {0: "Channel 1",
+ 1: "Channel 2",
+ 2: "Channel 1&2",
+ 3: "No channel",
+ }
+
+EOVR = ECH
+
+EDOM = {0: 'Time',
+ 1: 'Frequency',
+ 2: 'Voltage (amplitude)',
+ }
+
+EVLT = {0: "Peak",
+ 1: "RMS",
+ 2: "Volt (indicates peak only)",
+ }
+
+EAMP = {0: "Volts",
+ 1: "Volts squared",
+ 2: "PSD (V²/Hz)",
+ 3: "ESD (V²s/Hz)",
+ 4: "PSD¹² (V/Hz¹²)",
+ 5: "No unit",
+ 6: "Unit volts",
+ 7: "Unit volts²",
+ }
+
+EXAXIS= {0: "No units",
+ 1: "Hertz",
+ 2: "RPM",
+ 3: "Orders",
+ 4: "Seconds",
+ 5: "Revs",
+ 6: "Degrees",
+ 7: "dB",
+ 8: "dBV",
+ 9: "Volts",
+ 10: "V Hz¹²",
+ 11: "Hz/s",
+ 12: "V/EU",
+ 13: "Vrms",
+ 14: "V²/Hz",
+ 15: "%",
+ 16: "Points",
+ 17: "Records",
+ 18: "Ohms",
+ 19: "Hertz/octave",
+ 20: "Pulse/Rev",
+ 21: "Decades",
+ 22: "Minutes",
+ 23: "V²s/Hz",
+ 24: "Octave",
+ 25: "Seconds/Decade",
+ 26: "Seconds/Octave",
+ #...
+ }
+
+EMEAS = {0: "Linear resolution",
+ 1: "Log resolution",
+ 2: "Swept sine",
+ 3: "Time capture",
+ 4: "Linear resolution throughput",
+ }
+
+EDEMOD1 = {45: "AM",
+ 46: "FM",
+ 47: "PM",
+ }
+
+EDEMOD2 = EDEMOD1
+
+EAVG = {0: "No data",
+ 1: "Not averaged",
+ 2: "Averaged",}
+
+
+
+EWIN = {0: "N/A",
+ 1: "Hann",
+ 2: "Flat top",
+ #...
+ }
+
+HEADER = [ ("Display function", EDSP, 'h', 2),
+ ('Number of elements', int, 'h', 2),
+ ('Displayed elements', int, 'h', 2),
+ ('Number of averages', int, 'h', 2),
+ ('Channel selection', ECH, 'h', 2),
+ ('Overflow status', EOVR, 'h', 2),
+ ('Overlap percentage', int, 'h', 2),
+ ('Domain', EDOM, 'h', 2),
+ ('Volts peak/rms', EVLT, 'h', 2),
+ ('Amplitude units', EAMP, 'h', 2),
+ ('X axis units', EXAXIS, 'h', 2),
+ ('Auto math label', str, 's', 14),
+ ('Trace label', str, 's', 22),
+ ('EU label 1', str, 's', 6),
+ ('EU label 2', str, 's', 6),
+ ('Float/Interger', bool, 'h', 2),
+ ('Complex/Real', bool, 'h', 2),
+ ('Live/Recalled', bool, 'h', 2),
+ ('Math result', bool, 'h', 2),
+ ('Real/Complex input', bool, 'h', 2),
+ ('Log/Linear data', bool, 'h', 2),
+ ('Auto math', bool, 'h', 2),
+ ('Real time status', bool, 'h', 2),
+ ('Measurement mode', EMEAS, 'h', 2),
+ ('Window', EWIN, 'h', 2),
+ ('Demod type channel 1', EDEMOD1, 'h', 2),
+ ('Demod type channel 2', EDEMOD2, 'h', 2),
+ ('Demod active channel 1', bool, 'h', 2),
+ ('Demod active channel 2', bool, 'h', 2),
+ ('Average status', EAVG, 'h', 2),
+ ('Not used', int, 'hh', 4),
+ ('Samp freq/2 (real)', decode_float, None, 4),
+ ('Samp freq/2 (imag)', decode_float, None, 4),
+ ('Not used', decode_float, None, 4),
+ ('Delta X-axis', decode_float, None, 4),
+ ('Max range', decode_float, None, 4),
+ ('Start time value', decode_float, None, 4),
+ ('Expon wind const 1', decode_float, None, 4),
+ ('Expon wind const 2', decode_float, None, 4),
+ ('EU value chan 1', decode_float, None, 4),
+ ('EU value chan 2', decode_float, None, 4),
+ ('Trig delay chan 1', decode_float, None, 4),
+ ('Trig delay chan 2', decode_float, None, 4),
+ ('Start freq value', decode_float, None, 8),
+ ('Start data value', decode_float, None, 8),
+ ]
+
+def decode_file(filename):
+ d = open(filename).read()
+
+ typ = d[:2]
+ assert typ == "#A"
+
+ totlen = struct.unpack('>h', d[2:4])[0]
+ idx = 4
+ tt=0
+ header = {}
+ for i, (nam, dtype, fmt, nbytes) in enumerate(HEADER):
+ if dtype == str:
+ val = decode_string(d[idx:])
+ else:
+ if fmt:
+ v = struct.unpack('>'+fmt, d[idx: idx+nbytes])[0]
+ if isinstance(dtype, dict):
+ val = dtype.get(int(v), "N/A")
+ else:
+ val = dtype(v)
+ else:
+ val = dtype(d[idx: idx+nbytes])
+
+ print idx, hex(idx), nam, ":", val
+ header[nam] = val
+ idx += nbytes
+
+ resu = []
+
+ for i in range(header["Number of elements"]):
+ resu.append(decode_float(d[idx: idx+4]))
+ idx += 4
+
+ #print "resu = ", resu
+ #return
+ import pylab
+ import numpy
+ resu = numpy.array(resu, dtype=float)
+ print "max = ", max(resu)
+ #xr = numpy.linspace(0, header['Delta X-axis'], len(resu))
+ sf = header['Start freq value']
+ xr = numpy.linspace(sf, sf+20000, len(resu))
+ mn = min(resu[resu>0])
+ resu[resu==0] = mn
+ pylab.plot(xr, 10*numpy.log10(resu))
+ pylab.show()
+
+ # tt=0
+ # for i, (nam, dtype, nbytes) in enumerate(HEADER):
+ # if dtype == str:
+ # nb = ord(struct.unpack('c', d[idx])[0])
+ # val = d[idx+1:idx+1+nb]
+ # else:
+ # v = struct.unpack('>d', d[idx: idx+(nbytes*4)])[0]
+ # if isinstance(dtype, dict):
+ # val = dtype.get(int(v), "N/A")
+ # else:
+ # val = dtype(v)
+ # print idx, nam, ":", val
+ # idx += nbytes*4
+
+
+
+
+if __name__ == "__main__":
+ import sys
+ decode_file(sys.argv[1])
+
+
+
+ 