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.\" RCSid "$Id: histo.1,v 1.5 2007/07/12 14:58:52 greg Exp $" |
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.TH HISTO 1 9/6/96 RADIANCE |
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.SH NAME |
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histo - compute 1-dimensional histogram of N data columns |
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.SH SYNOPSIS |
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.B "histo [-c][-p] xmin xmax nbins" |
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.br |
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.B "histo [-c][-p] imin imax" |
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.SH DESCRIPTION |
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.I Histo |
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bins columnular data on the standard input between the given minimum |
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and maximum values. |
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If three command line arguments are given, the third is taken as the |
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number of data bins between the first two real numbers. |
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If only two arguments are given, they are both assumed to be integers, |
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and the number of data bins will be equal to their difference plus one. |
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The bins are always of equal size. |
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.PP |
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The output is N+1 columns of data (for N columns input), where the |
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first column is the centroid of each division, and each row |
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corresponds to the frequencies for each column around that value. |
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.PP |
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If the |
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.I \-c |
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option is present, then |
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.I histo |
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computes the cumulative histogram for each column instead of the |
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straight frequencies. |
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The upper value of each bin is printed also instead of the centroid. |
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This may be useful in computing percentiles, for example. |
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Values below the minimum specified are still counted in the cumulative |
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total. |
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.PP |
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The |
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.I \-p |
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option tells |
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.I histo |
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to report the percentage of the total number of input lines rather |
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than the absolute counts. |
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In the case of a cumulative total, this yeilds the percentile values |
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directly. |
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Values above the maximum are counted as well as values below in |
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this case. |
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.PP |
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All input data is interpreted as real values, and columns must be |
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white-space separated. |
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If any value is less than the minimum or greater than the maximum, |
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it will be ignored unless the |
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.I \-c |
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option is specified. |
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.SH EXAMPLE |
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To count data values between \-1 and 1 in 50 bins: |
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.IP "" .2i |
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histo \-1 1 50 < input.dat |
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.PP |
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To count frequencies of integers between 0 and 255: |
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.IP "" .2i |
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histo 0 255 < input.dat |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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cnt(1), neaten(1), rcalc(1), rlam(1), tabfunc(1), total(1) |
