| 1 | greg | 1.7 | .\" RCSid "$Id: histo.1,v 1.6 2007/09/04 17:36:40 greg Exp $" | 
| 2 | greg | 1.1 | .TH HISTO 1 9/6/96 RADIANCE | 
| 3 |  |  | .SH NAME | 
| 4 |  |  | histo - compute 1-dimensional histogram of N data columns | 
| 5 |  |  | .SH SYNOPSIS | 
| 6 | greg | 1.3 | .B "histo [-c][-p] xmin xmax nbins" | 
| 7 | greg | 1.1 | .br | 
| 8 | greg | 1.3 | .B "histo [-c][-p] imin imax" | 
| 9 | greg | 1.1 | .SH DESCRIPTION | 
| 10 |  |  | .I Histo | 
| 11 |  |  | bins columnular data on the standard input between the given minimum | 
| 12 |  |  | and maximum values. | 
| 13 |  |  | If three command line arguments are given, the third is taken as the | 
| 14 |  |  | number of data bins between the first two real numbers. | 
| 15 |  |  | If only two arguments are given, they are both assumed to be integers, | 
| 16 |  |  | and the number of data bins will be equal to their difference plus one. | 
| 17 |  |  | The bins are always of equal size. | 
| 18 |  |  | .PP | 
| 19 |  |  | The output is N+1 columns of data (for N columns input), where the | 
| 20 |  |  | first column is the centroid of each division, and each row | 
| 21 |  |  | corresponds to the frequencies for each column around that value. | 
| 22 |  |  | .PP | 
| 23 |  |  | If the | 
| 24 |  |  | .I \-c | 
| 25 |  |  | option is present, then | 
| 26 |  |  | .I histo | 
| 27 |  |  | computes the cumulative histogram for each column instead of the | 
| 28 |  |  | straight frequencies. | 
| 29 |  |  | The upper value of each bin is printed also instead of the centroid. | 
| 30 |  |  | This may be useful in computing percentiles, for example. | 
| 31 | greg | 1.3 | Values below the minimum specified are still counted in the cumulative | 
| 32 |  |  | total. | 
| 33 |  |  | .PP | 
| 34 |  |  | The | 
| 35 |  |  | .I \-p | 
| 36 |  |  | option tells | 
| 37 |  |  | .I histo | 
| 38 |  |  | to report the percentage of the total number of input lines rather | 
| 39 | greg | 1.5 | than the absolute counts. | 
| 40 | greg | 1.7 | In the case of a cumulative total, this yields the percentile values | 
| 41 | greg | 1.3 | directly. | 
| 42 |  |  | Values above the maximum are counted as well as values below in | 
| 43 |  |  | this case. | 
| 44 | greg | 1.1 | .PP | 
| 45 |  |  | All input data is interpreted as real values, and columns must be | 
| 46 |  |  | white-space separated. | 
| 47 |  |  | If any value is less than the minimum or greater than the maximum, | 
| 48 | greg | 1.3 | it will be ignored unless the | 
| 49 |  |  | .I \-c | 
| 50 |  |  | option is specified. | 
| 51 | greg | 1.1 | .SH EXAMPLE | 
| 52 | greg | 1.6 | To count data values between \-1 and 1 in 50 bins: | 
| 53 | greg | 1.1 | .IP "" .2i | 
| 54 | greg | 1.6 | histo \-1 1 50 < input.dat | 
| 55 | greg | 1.1 | .PP | 
| 56 |  |  | To count frequencies of integers between 0 and 255: | 
| 57 |  |  | .IP "" .2i | 
| 58 |  |  | histo 0 255 < input.dat | 
| 59 |  |  | .SH AUTHOR | 
| 60 |  |  | Greg Ward | 
| 61 |  |  | .SH "SEE ALSO" | 
| 62 | greg | 1.4 | cnt(1), neaten(1), rcalc(1), rlam(1), tabfunc(1), total(1) |