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



NNAAMMEE
       rr..ppaattcchh	 -  Creates a composite raster map layer by using
       known category values from one (or more) map  layer(s)  to
       fill in areas of "no data" in another map layer.
       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..ppaattcchh
       rr..ppaattcchh hheellpp
       rr..ppaattcchh [--qqzz] iinnppuutt==_n_a_m_e[,_n_a_m_e,...]  oouuttppuutt==_n_a_m_e

DDEESSCCRRIIPPTTIIOONN
       The  GRASS program _r_._p_a_t_c_h allows the user to assign known
       data values from other raster map layers to the _"_n_o  _d_a_t_a_"
       areas  (those  assigned	category value NULL/0) in another
       raster map layer.  This program is  useful  for	making	a
       composite  raster  map layer from two or more adjacent map
       layers, for filling in "holes" in  a  raster  map  layer's
       data (e.g., in digital elevation data), or for updating an
       older map layer with more recent data.  The  current  geo-
       graphic region definition and mask settings are respected.


       The program will be  run  non-interactively  if	the  user
       specifies program arguments on the command line, using the
       form: rr..ppaattcchh [--qqzz] iinnppuutt==_n_a_m_e[,_n_a_m_e,...]  oouuttppuutt==_n_a_m_e

       where each input _n_a_m_e is the name of a raster map layer to
       be  patched,  the  output _n_a_m_e is the name assigned to the
       new composite raster  map  layer  containing  the  patched
       result,	and the (optional) --qq flag directs _r_._p_a_t_c_h to run
       quietly.


       The first _n_a_m_e listed in the string  iinnppuutt==_n_a_m_e,_n_a_m_e,_n_a_m_e,
       ...  is	the  name  of the base map whose zero data values
       will be attempted to be filled by non-zero data values  in
       the second through tenth input _n_a_m_e maps listed.  The sec-
       ond through tenth input _n_a_m_e maps will be used  to  supply
       remaining  missing  (zero) data values for the first input
       map _n_a_m_e, based on the order in which they are  listed  in
       the string iinnppuutt==_n_a_m_e,_n_a_m_e,_n_a_m_e, ...


       Alternately,  the user can simply type rr..ppaattcchh on the com-
       mand line, without program arguments. In  this  case,  the
       user  will  be prompted for the flag setting and parameter
       values using the standard GRASS _p_a_r_s_e_r interface.

   FFllaagg::
       --qq     Directs that _r_._p_a_t_c_h run quietly, suppressing  out-
	      put  of  messages  on  program progress to standard
	      output.

       --zz     Use zero (0) for transparency instead of NULL.


   PPaarraammeetteerrss::
       iinnppuutt==_n_a_m_e,_n_a_m_e,...
	      The name(s) of between one and 200 existing  raster
	      map layers to be patched together. The first of the
	      maximal 200 maps listed will be used as a base map,
	      and  the	second	through tenth maps listed will be
	      used to supply missing (zero) category  values  for
	      the first map.

       oouuttppuutt==_n_a_m_e
	      The  name  of  the  new  raster  map to contain the
	      resultant patched output.


EEXXAAMMPPLLEE
       Below, the raster map layer on the  far	left  is  ppaattcchheedd
       with  the  middle  (_p_a_t_c_h_i_n_g) raster map layer, to produce
       the _c_o_m_p_o_s_i_t_e raster map layer on the right.

	 1 1 1 0 2 2 0 0    0 0 1 1 0 0 0 0    1 1 1 1 2 2 0 0
	 1 1 0 2 2 2 0 0    0 0 1 1 0 0 0 0    1 1 1 2 2 2 0 0
	 3 3 3 3 2 2 0 0    0 0 0 0 0 0 0 0    3 3 3 3 2 2 0 0
	 3 3 3 3 0 0 0 0    4 4 4 4 4 4 4 4    3 3 3 3 4 4 4 4
	 3 3 3 0 0 0 0 0    4 4 4 4 4 4 4 4    3 3 3 4 4 4 4 4
	 0 0 0 0 0 0 0 0    4 4 4 4 4 4 4 4    4 4 4 4 4 4 4 4

       Switching the _p_a_t_c_h_e_d and the _p_a_t_c_h_i_n_g raster  map  layers
       produces the following results:

	 0 0 1 1 0 0 0 0    1 1 1 0 2 2 0 0    1 1 1 1 2 2 0 0
	 0 0 1 1 0 0 0 0    1 1 0 2 2 2 0 0    1 1 1 1 2 2 0 0
	 0 0 0 0 0 0 0 0    3 3 3 3 2 2 0 0    3 3 3 3 2 2 0 0
	 4 4 4 4 4 4 4 4    3 3 3 3 0 0 0 0    4 4 4 4 4 4 4 4
	 4 4 4 4 4 4 4 4    3 3 3 0 0 0 0 0    4 4 4 4 4 4 4 4
	 4 4 4 4 4 4 4 4    0 0 0 0 0 0 0 0    4 4 4 4 4 4 4 4


NNOOTTEESS
       Frequently,  this  program is used to patch together adja-
       cent map layers which have been digitized separately.  The
       programs  _v_._m_k_q_u_a_d_s and _v_._m_k_g_r_i_d can be used to make adja-
       cent maps align neatly.


       The user should check the current geographic  region  set-
       tings  before  running  _r_._p_a_t_c_h, to ensure that the region
       boundaries  encompass  all  of  the  data  desired  to  be
       included in the composite map.


       Use  of	_r_._p_a_t_c_h is generally followed by use of the GRASS
       programs _g_._r_e_m_o_v_e and _g_._r_e_n_a_m_e; _g_._r_e_m_o_v_e is used to remove
       the   original	(un-patched)  raster  map  layers,  while
       _g_._r_e_n_a_m_e is used to then assign to the newly-created  com-
       posite (patched) raster map layer the name of the original
       raster map layer.


       _r_._p_a_t_c_h creates support files for the  patched,	composite
       output map.

SSEEEE AALLSSOO
       _g_._r_e_g_i_o_n

       _g_._r_e_m_o_v_e

       _g_._r_e_n_a_m_e

       _r_._m_a_p_c_a_l_c

       _r_._s_u_p_p_o_r_t

       _v_._m_k_g_r_i_d

       _v_._m_k_q_u_a_d_s

       _p_a_r_s_e_r

AAUUTTHHOORR
       Michael	 Shapiro,   U.S.  Army	Construction  Engineering
       Research Laboratory
       -z flag by Huidae Cho

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_3_/_0_4 _1_0_:_3_2_:_0_5 _$



GRASS 5.0					       r.patch(1)
