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



NNAAMMEE
       rr..rreessccaallee   -  Rescales	the  range  of category values 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..rreessccaallee
       rr..rreessccaallee hheellpp
       rr..rreessccaallee  [--qqzz]  iinnppuutt==_n_a_m_e  [ffrroomm==_m_i_n_,_m_a_x]   oouuttppuutt==_n_a_m_e   ttoo==_m_i_n_,_m_a_x
       [ttiittllee=="_p_h_r_a_s_e"]

DDEESSCCRRIIPPTTIIOONN
       The  _r_._r_e_s_c_a_l_e  program rescales the range of category values appearing
       in a raster map layer.  A new raster map layer, and an appropriate cat-
       egory  file  and  color table based upon the original raster map layer,
       are generated with category labels that reflect the  original  category
       values that produced each category.  This command is useful for produc-
       ing representations with a reduced number of categories from  a	raster
       map  layer  with  a  large  range of category values (e.g., elevation).
       _R_e_s_c_a_l_e_d map layers are appropriate for use in such GRASS  programs  as
       _r_._s_t_a_t_s, _r_._r_e_p_o_r_t, and _r_._c_o_i_n.

OOPPTTIIOONNSS
       _r_._r_e_s_c_a_l_e  will	be run non-interactively if the user specifies program
       arguments on the command line, using the form:


       rr..rreessccaallee  [--qqzz]  iinnppuutt==_n_a_m_e  [ffrroomm==_m_i_n_,_m_a_x]   oouuttppuutt==_n_a_m_e   ttoo==_m_i_n_,_m_a_x
       [ttiittllee==""_p_h_r_a_s_e"]


       Alternately, the user can simply type: rr..rreessccaallee

       on  the command line without program arguments.	In this case, the user
       will be prompted for parameter values using  the  standard  GRASS  user
       interface described in the manual entry for _p_a_r_s_e_r.

   FFllaagg::
       --qq     Run  quietly,  without  printing messages on program progress to
	      the user's terminal.


       --zz     Use zero (0) for transparency instead of NULL,  that  means  set
	      values outside range to zero (0) instead of NULL.


   PPaarraammeetteerrss::
       iinnppuutt==_n_a_m_e
	      The name of the raster map layer whose category values are to be
	      rescaled.

       ffrroomm==_m_i_n_,_m_a_x
	      The input map range to be rescaled.
	      Default:	The full range of the input map layer.

       oouuttppuutt==_n_a_m_e
	      The name of the new, rescaled raster map layer.

       ttoo==_m_i_n_,_m_a_x
	      The output map range (after rescaling).

       ttiittllee== Title for new output raster map layer.


EEXXAAMMPPLLEE
       To rescale an elevation raster map layer with category  values  ranging
       from  1090  meters  to  1800 meters into the range 0-255, the following
       command line could be used:  rr..rreessccaallee  iinnppuutt==elevation	ffrroomm==1090,1800
       oouuttppuutt==elevation.255 ttoo==0,255


NNOOTTEESS
       Category  values  that  fall  beyond  the input range will become NULL.
       This allows the user to select a subset	of  the  full  category  value
       range  for  rescaling if desired.  This also means that the user should
       know the category value range for the input raster map layer.  The user
       can  request  the  _r_._r_e_s_c_a_l_e  program  to  determine this range, or can
       obtain it using the _r_._i_n_f_o command.  If the  category  value  range  is
       determined using _r_._r_e_s_c_a_l_e, the input raster map layer is examined, and
       the minimum and maximum non-NULL category values are  selected  as  the
       input range.

SSEEEE AALLSSOO
       _r_._c_o_i_n, _r_._d_e_s_c_r_i_b_e, _r_._i_n_f_o, _r_._m_a_p_c_a_l_c, _r_._r_e_c_l_a_s_s, _r_._r_e_p_o_r_t, _r_._r_e_s_a_m_p_l_e,
       _r_._s_t_a_t_s, and _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_: _$_D_a_t_e_: _2_0_0_2_/_0_3_/_0_1 _0_0_:_0_8_:_3_1 _$



GRASS 5.0							  r.rescale(1)
