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



NNAAMMEE
       _r_._r_e_c_o_d_e - recode raster maps

       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..rreeccooddee [--aadd] iinnppuutt_=_n_a_m_e oouuttppuutt_=_n_a_m_e [ttiittllee_=_n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       _r_._r_e_c_o_d_e  creates  an  output  map layer based on an input
       raster map layer. The output map layer will be a  recoding
       of  the	input  map  layer  based on recode rules input to
       _r_._r_e_c_o_d_e. A _t_i_t_l_e for the output map layer may be (option-
       ally) specified by the user.


       The recode  rules are read from standard input (i.e., from
       the keyboard, redirected from a	file,  or  piped  through
       another program).


       The  program  will  be  run  non-interactively if the user
       specifies the name of the raster map layer to be  recoded,
       the  _n_a_m_e  of  an  output  layer  to hold recoded map, and
       (optionally) the name of a title for the output map.

   FFllaagg::
       --aa     Align the current region to the input map

       --dd     Force output to double map type (DCELL)


   PPaarraammeetteerrss::
       iinnppuutt  Raster map to be recoded

       oouuttppuutt Name for the resulting raster map

       ttiittllee  Title for the resulting raster map

       Enter a rule in one of these formats:

	   old_low:old_high:new_low:new_high
	   old_low:old_high:new_val  (i.e. new_high == new_low)
	   *:old_val:new_val	     (interval [inf, old_val])
	   old_val:*:new_val	     (interval [old_val, inf])

       _r_._r_e_c_o_d_e is loosely based on r.reclass and uses the  GRASS
       reclass	library  to  convert the rasters. It has routines
       for converting to every	possible  combination  of  raster
       (eg.  int  to  double,  double  to  float, etc).  Standard
       floating point raster precision is float, with  _-_d  double
       precision will be written.

       There are four basic routines that it accepts:

	      old-low  to old-high is reclassed to new-low to new
	      high , where the user provides all four values. The
	      program  figures	on  the  fly  what type of raster
	      should be created.

	      old-low to old-high is reclassed to  a  single  new
	      value. Anything outside the range is null.

	       *  to  old-high	will reclass everything less than
	      old-high to a single new value.

	       old-low to * will reclass everything greater  than
	      old-low to a single new value.

       These  four  sets of arguments can be given on the command
       line, or piped via stdin or a file. More than one  set  of
       arguments is accepted.

EEXXAAMMPPLLEESS
       MMaapp ttyyppee ccoonnvveerrssiioonn

       To  simply  convert  a  raster between formats (eg. int to
       float) the user would use the first argument. For example

       10:1500:0.1:15.0

       would convert an old raster with range between 10 and 1500
       to a float raster with range bewteen 0.1 and 15.0.


       VVaalluuee rreeppllaacceemmeenntt

       r.recode  can  be  used to replace existing cell values by
       others. The formatting is as described above. In following
       example	the  values  1,  2 and 3 are replaced by 1.1, 7.5
       resp. 0.4:


	   r.recode in=oldmap out=newmap << EOF
	   1:1:1.1:1.1
	   2:2:7.5:7.5
	   3:3:0.4:0.4
	   EOF


AAUUTTHHOORR
       CERL

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_3_/_0_1 _0_0_:_2_7_:_4_5 _$



GRASS 5.0					      r.recode(1)
