NAME

       r.describe  - Prints terse list of category values found in a raster map layer.

KEYWORDS

       raster, metadata

SYNOPSIS

       r.describe
       r.describe help
       r.describe [-1rndiq] map=name  [nv=string]   [nsteps=integer]   [--verbose]  [--quiet]

   Flags:
       -1
           Print the output one value per line

       -r
           Only print the range of the data

       -n
           Suppress reporting of any NULLs

       -d
           Use the current region

       -i
           Read fp map as integer

       -q
           Run quietly

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       map=name
           Name of input raster map

       nv=string
           String representing no data cell value
           Default: *

       nsteps=integer
           Number of quantization steps
           Default: 255

DESCRIPTION

       r.describe  prints a terse listing of category values found in a user-specified raster map
       layer.

       r.describe ignores the current geographic region and mask, and reads the  full  extent  of
       the  input  raster map.  This functionality is useful if the user intends to reclassify or
       rescale the data, since these functions (r.reclass and r.rescale) also ignore the  current
       geographic region and mask.

       The nv parameter sets the string to be used to represent NULL values in the module output;
       the default is '*'.

       The nsteps parameter sets the number of quantisation steps to divide into the input raster
       map.

NOTES

   FLAGS
       If  the user selects the -r flag, a range of category values found in the raster map layer
       will be printed. The range is divided into three groups: negative, positive, and zero.  If
       negative  values  occur,  the  minimum  and  maximum  negative  values will be printed. If
       positive values occur, the minimum and maximum positive values will be  printed.  If  zero
       occurs,  this  will be indicated. The range report will generally run faster than the full
       list (the default output).

       The -d flag can be used to force r.describe to respect the  current  region  extents  when
       repoting  raster  map  categories.  The default behavior is to read the full extent of the
       input raster map.

       If the -1 flag is specified, the output appears with one category value/range per line.

       The -n flag suppresses the reporting of NULL values.

EXAMPLES

       The following examples are from the Spearfish60 sample Location:

       # Print the full list of raster map categories:
       r.describe landcover.30m
       * 11 21-23 31 32 41-43 51 71 81-83 85 91 92

       # Print the raster range only:
       r.describe -r landcover.30m
       11 thru 92
       *
        # Print raster map category range, suppressing nulls:
       r.describe -n landcover.30m
       11 21-23 31 32 41-43 51 71 81-83 85 91 92

       # Print raster map categories, one category per line:
       r.describe -1 geology
       *
       1
       2
       3
       4
       5
       6
       7
       8
       9

SEE ALSO

        g.region, r.mask, r.reclass, r.report, r.rescale, r.stats, r.univar

AUTHOR

       Michael Shapiro, U.S. Army Construction Engineering Research Laboratory

       Last changed: $Date: 2008-05-16 12:09:06 -0700 (Fri, 16 May 2008) $

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