NAME

       d.histogram  - Displays a histogram in the form of a pie or bar chart for a user-specified raster map.

KEYWORDS

       display, histogram, statistics

SYNOPSIS

       d.histogram
       d.histogram --help
       d.histogram  [-nc] map=name  [style=string]   [color=name]   [bgcolor=name]   [nsteps=integer]   [--help]
       [--verbose]  [--quiet]  [--ui]

   Flags:
       -n
           Display information for null cells

       -c
           Report for ranges defined in cats file (fp maps only)

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       map=name [required]
           Raster map for which histogram will be displayed

       style=string
           Indicate if a pie or bar chart is desired
           Options: pie, bar
           Default: bar

       color=name
           Color for text and axes
           Either a standard color name or R:G:B triplet
           Default: black

       bgcolor=name
           Background color
           Either a standard color name, R:G:B triplet, or "none"
           Default: white

       nsteps=integer
           Number of steps to divide the data range into (fp maps only)
           Default: 255

DESCRIPTION

       d.histogram displays the category-value distribution for a user-specified raster map layer, in  the  form
       of a bar chart or a pie chart.  The display will be displayed in the active display frame on the graphics
       monitor, using the colors in the raster map layer’s color table.  The program determines the raster map’s
       category value distribution by counting cells.

NOTES

       d.histogram respects the current geographic region settings and the current MASK (if one exists).

       d.histogram uses the colors in the map’s color look-up table (i.e., the map’s colr or colr2 file).

EXAMPLES

       Running the command below will generate the bar graph shown in the figure:
       g.region raster=elevation -p
       d.mon wx0
       d.histogram map=elevation
       Figure: Bar graph histogram for elevation map

       Running the command below will generate the pie graph shown in the figure:
       g.region raster=landuse96_28m -p
       d.histogram map=landuse96_28m style=pie
       Figure: Pie graph histogram for landuse map

SEE ALSO

        d.colortable, d.frame, d.graph, d.linegraph, d.mon, d.polar, g.region, r.stats

AUTHOR

       Dave Johnson
       DBA Systems, Inc.
       10560 Arrowhead Drive
       Fairfax, Virginia 22030

SOURCE CODE

       Available at: d.histogram source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual