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 val-
       ues appearing in a raster map layer.   A  new  raster  map
       layer,  and  an	appropriate category 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  use-
       ful for producing 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 speci-
       fies 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==eleva-
       tion.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)
