ihist [-v] < input.shorts > output.txtIHIST(1)
NAME
ihist - compute a histogram and bit statistics for a stream of short integers
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SYNOPSIS
DESCRIPTION
ihist reads a stream of 16-bit signed short integers from standard input and writes statistics about the data to standard output. It reports the total number of values read, the minimum and maximum values encountered, and a per-bit tally showing how often each of the 16 bits was set across the entire stream (with each count expressed as a fraction of the total). It also reports the number of distinct levels (unique values) seen out of the 65,536 possible, as a percentage.
The companion tool istats(1) reports running statistical moments (mean, variance, and so on) for the same short integer stream, while imod(1) applies arithmetic operations to it.
OPTIONS
- -v
-
Verbose. In addition to the summary statistics, print the full histogram as one "value count" pair per line for every distinct value that occurred.
EXAMPLES
Example 1. Inspect the dynamic range of sampled audio
ihist < samples.shortsReports the min/max range, the per-bit usage, and the percentage of the 65,536 possible levels actually present in samples.shorts, which is a quick way to tell whether a 16-bit sample stream is using its full dynamic range or only a narrow band of values.
Example 2. Produce a full histogram for plotting
ihist -v < samples.shorts | tail -n +22 > histogram.datGenerates a complete "value count" listing and skips the leading summary lines so that histogram.dat contains only the per-value frequency pairs, ready to be fed to a plotting program.
SEE ALSO
brlcad(1), istats(1), imod(1), ustats(1), bw-d(1)
AUTHOR
BRL-CAD Team
COPYRIGHT
This software is Copyright (c) 1989-2026 by the United States Government as represented by U.S. Army Research Laboratory.
BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org