r.describe(1)	       Grass User's Manual	    r.describe(1)



NNAAMMEE
       rr..ddeessccrriibbee   -  Prints terse list of category values found
       in a raster map layer.
       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..ddeessccrriibbee
       rr..ddeessccrriibbee hheellpp
       rr..ddeessccrriibbee [--11rrqqdd] mmaapp==_n_a_m_e[nnvv==_s_t_r_i_n_g][nnsstteeppss==_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       _r_._d_e_s_c_r_i_b_e prints a terse listing of category values found
       in a user-specified raster map layer.

OOPPTTIIOONNSS
       The  program  will  be  run non-interactively, if the user
       specifies the name of a raster map layer and  any  desired
       flags  on  the  command	line,  using  the form rr..ddeessccrriibbee
       [--11rrqqdd] mmaapp==_n_a_m_e

       where the map _n_a_m_e is the name of a raster map layer whose
       categories  are	to be described, and the (optional) flags
       --11, --rr, --qq, and --dd have the meanings described below.


       Alternately, the user can simply type  rr..ddeessccrriibbee  on  the
       command	line,  without	program arguments.  In this case,
       the user will be prompted for needed flag settings and the
       parameter value using the standard GRASS _p_a_r_s_e_r.

   PPRROOGGRRAAMM UUSSEE
       The  user  can  select  one  of	the  following two output
       reports from _r_._d_e_s_c_r_i_b_e:

       (1) RANGE.
	      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 neg-
	      ative values will be printed.  If  positive  values
	      occur, the minimum and maximum positive values will
	      be printed.  If zero occurs,  this  will	be  indi-
	      cated.

       (2) FULL LIST.
	      A  list  of  all category values that were found in
	      the raster map layer will be printed.


       The following sample output from _r_._d_e_s_c_r_i_b_e: 0 2-4 10-13

       means that category data values 0, 2  through  4,  and  10
       through 13 occurred in the named map layer.

       The  user  must choose to read the map layer in one of two
       ways:

       (1) DIRECTLY.
	      The current geographic region and mask are  ignored
	      and the full raster map layer is read.  This method
	      is useful if the	user  intends  to  _r_e_c_l_a_s_s_i_f_y  or
	      _r_e_s_c_a_l_e  the data, since these functions (_r_._r_e_c_l_a_s_s
	      and _r_._r_e_s_c_a_l_e) also ignore the  current  _g_e_o_g_r_a_p_h_i_c
	      _r_e_g_i_o_n and _m_a_s_k.

       (2) REGIONED and MASKED.
	      The map layer is read within the current geographic
	      region, masked by the current mask.


   NNOONN--IINNTTEERRAACCTTIIVVEE PPRROOGGRRAAMM UUSSEE
       _r_._d_e_s_c_r_i_b_e examines a user-chosen raster  map  layer.   If
       run  non-interactively, the layer name must be supplied on
       the command line.


       A compact list of category values that were found  in  the
       data layer will be printed.


       Following is a sample output: 0 2-4 10-13


   FFllaaggss::
       --ll     Print the output one value per line, instead of the
	      default short form.  In the above example,  the  --11
	      option would output:

	      0
	      2
	      3
	      4
	      10
	      11
	      12
	      13


       --rr     Only  print the range of the data.  The highest and
	      lowest positive values, and the highest and  lowest
	      negative	values, are output. In the above example,
	      the --rr option would output: 0 2 13



       If the --11 option is also  specified,  the  output  appears
       with one category value per line.

       --qq     Quiet.  The  --qq  option  will tell r.describe to be
	      silent while reading the raster file.  If not spec-
	      ified,  program  percentage-completed  messages are
	      printed.

       --dd     Use the current geographic region  settings.   Nor-
	      mally,   _r_._d_e_s_c_r_i_b_e   will   read  the  data  layer
	      directly, ignoring both the current region settings
	      and  mask.   The --dd option tells _r_._d_e_s_c_r_i_b_e to read
	      the map layer in the current region masked  by  the
	      current mask (if any).


   PPaarraammeetteerrss::
       mmaapp==_n_a_m_e
	      Name of raster map.

       nnvv==_s_t_r_i_n_g
	      String representing no data cell value.

       nnsstteeppss==_v_a_l_u_e
	      Number of quantization steps.


NNOOTTEESS
       The  range  report will generally run faster than the full
       list.

SSEEEE AALLSSOO
       _p_a_r_s_e_r

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

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_4 _$



GRASS 5.0					    r.describe(1)
