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histogram -- Plot or list the histogram of a table column, image, or list.


histogram input


This task will plot the histogram (i.e., frequency distribution) of an input file. Input files can be tables, images, or text files. The task first computes the histogram and then either plots or lists it. Plot limits can be specified, or the entire range can be plotted.

It is possible to specify limits such that the bin values decrease with bin number, for example, z1 will be less than z2, etc. It is not possible to reverse the sense of the bins when using INDEF to let the task find the extreme data value.


input [file name]
Name of the input table, image, or text file. File name extensions can be omitted, unless there is a danger of confusion (such as when an image and table both have the same root name). The task automatically determines the input file type by first trying to read it as a table, then an image, and finally, as a text file.
(colname) [string]
The name of the column to use if the input file is a table.
(nbins = 512) [integer, min=1]
The number of histogram bins to use. Data outside the range z1 to z2 are ignored.
(z= INDEF) [real]
The minimum data value to use. Note that this is different from the central value of the first bin. If z1 is INDEF, then the lowest value in input is used.
(z= INDEF) [real]
The maximum data value to use. This is different from the central value of the highest bin. If z2 is INDEF, then the highest value in input is used. If z1 and z2 are both set to INDEF (the default), then all data values will be used. If z1 > z2 then bin values will decrease, both in the plotted histogram and the listing to STDOUT. It is not possible to reverse the sense of the bins if either z1 or z2 is INDEF.
(listout = no) [boolean]
Print histogram values instead of plotting?
(title = Histogram: ) [string]
Title for plot. The file name will be appended to this string.
(xlabel = Data values) [string]
Title for the X axis.
(ylabel = Count) [string]
Title for the Y axis.
(logplot = yes) [boolean]
Should the Y axis of the plot be on a log scale?
(fulline = yes) [boolean]
Should the histogram lines be drawn to the base of the plot? Setting fulline=no will draw a stepped graph.
(cumulative = no) [boolean]
Should the cumulative histogram be calculated?
(dvpar = "") [pset]
Pset name for device parameters. Parameters can be individually changed from the command line or can be edited as a group using :e from eparam sgraph or from the cl, eparam dvpar or simply dvpar. Details about these parameters are available by typing "help dvpar".


1. Plot the histogram of the input file infile. If infile is a table then the column name must be given and its histogram plotted. Note that if there is a table and an image infile.hhh then table would be the file that is used because of the precedence in which file types are tested (see input parameter above). To avoid confusion the extension may be given explicitly.

   to> histogram infile

2. Specify limits on the input data such that bin values decrease:

  to> histogram infile z1=337 z2=100



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