Gamma LAT: Reference Manual

polyx, polyx_phase

ANSI-C programs: polyx.c, polyx_phase.c

NAME
polyx - Calculate mean and standard deviation for test-areas (polygon regions).

polyx_phase - Calculate mean and standard deviation for test-areas (polygon regions).

SYNOPSIS
polyx <data> <width> <polygon> <report> [mode_flag]

<data>	input data file (float)
<width>	number of samples/row
<polygon>	polygon data file
<report>/TD>	ascii text report on region statistics
mode_flag	report print mode: 0: i, mean, stdev (linear scale) (default) 1: i, mean, stdev (dB scale) 2: i, mean (linear scale) 3: i, mean (dB scale) 4: mean (linear scale) 5: mean (dB scale) 6: stdev (linear scale) 7: stdev (dB scale) 8: i, mean, stdev (linear scale, with exponent)

polyx_phase <data> <width> <polygon> <report>

<data>	(input) input data file (fcomplex)
<width>	number of samples per line
<polygon>	polygon data file
<report>/TD>	text report on region statistics (text format)

EXAMPLES
polyx 1352_1610.cc_ad 2500 1352_1610.poly 0 > 1352_1610.cc_ad.poly 1352_1610.cc_ad.rpt 0

Extracts coherence values and writes mean and stdev (absolute values) to output file. polyx 1352_1610.pow1 2500 1352_1610.poly 1 > 1352_1610.pow1.poly 1352_1610.pow1.rpt 1

Extracts backscatter values and writes mean and stdev (using dB scale) to output file.

DESCRIPTION
polyx and the other programs to extract signatures for test areas extract image values for pixels located in the polygon areas, calculate mean and standard deviations for each selected parameter, for each polygon region, and write the results to the standard output, respectively to the indicated text file.

Depending on the program the input files and the format of the output vary. polyx is the most general of the programs, permitting selection of linear or dB output. It also has an option for display of the output mean and/or standard deviation.

polyx_phase calculates mean and standard deviation of the interferometric phase for polygon regions. In addition mean and standard deviation of the 2 backscatter images are calculated. The results are expressed in linear scale. The program may be used to extract averaged phase differences between neighboring areas for example for the quantification of differential phase effects. The selection of the polygon regions is supported with the program polyras.
The output polyx and polyx_phase extract signatures of polygon regions and the statistics to text files that may be imported, displayed using plotting software such as gnuplot

SEE ALSO
typedef_ISP.h, polyras