readgssi thinks samples per meter is negative in this command?

[iannesbitt]

For some reason, this command yields a "must be positive" error like below, but ends up processing the file just fine.

$ readgssi -p 4 -x cm -z cm -g 3 -d 161 -i ./File____009.DZT 
2019-06-20 22:32:51 - ERROR: samples per meter must be positive
2019-06-20 22:32:51 - readgssi 0.0.12
2019-06-20 22:32:51 - reading...
2019-06-20 22:32:51 - input file:         ./File____009.DZT
2019-06-20 22:32:51 - success. header values:
2019-06-20 22:32:51 - system:             StructureScan Mini (system code 7)
2019-06-20 22:32:51 - antennas:           ['SS MINI', None, None, None]
2019-06-20 22:32:51 - ant 0 frequency:    1600 MHz
2019-06-20 22:32:51 - date created:       2017-04-08 08:40:22+00:00
2019-06-20 22:32:51 - date modified:      (never modified)
2019-06-20 22:32:51 - gps-enabled file:   no
2019-06-20 22:32:51 - number of channels: 1
2019-06-20 22:32:51 - samples per trace:  256
2019-06-20 22:32:51 - bits per sample:    32 signed
2019-06-20 22:32:51 - traces per second:  300.0
2019-06-20 22:32:51 - traces per meter:   161.00 (manually set - value from DZT: 393.70)
2019-06-20 22:32:51 - epsr:               8.0
2019-06-20 22:32:51 - speed of light:     1.06E+08 m/sec (35.35% of vacuum)
2019-06-20 22:32:51 - sampling depth:     0.4 m
2019-06-20 22:32:51 - "rhf_top":          0.0 m
2019-06-20 22:32:51 - offset to data:     1024 bytes
2019-06-20 22:32:51 - traces:             1131
2019-06-20 22:32:51 - seconds:            3.77000000
2019-06-20 22:32:51 - array dimensions:   256 x 1131
2019-06-20 22:32:51 - image stats
2019-06-20 22:32:51 - mean:               -422770.8228959438
2019-06-20 22:32:51 - stdev:              2769389.6223992216
2019-06-20 22:32:51 - lower color limit:  -8730939.690093609 [mean - (3 * stdev)]
2019-06-20 22:32:51 - upper color limit:  7885398.04430172 [mean + (3 * stdev)]
2019-06-20 22:32:51 - xmax: 702.4844720496894 Distance (cm), zmax: 40.63999950885773 Depth at $\epsilon_r$=8.0 (cm)
2019-06-20 22:32:51 - attempting to plot with colormap Greys
2019-06-20 22:32:52 - saving figure as ./File____009c0G3.png
2019-06-20 22:32:52 - showing matplotlib figure...

[iannesbitt]

assertion error was raised with wrong comparator (less than instead of greater than)