v.reclass(1)	       Grass User's Manual	     v.reclass(1)



NNAAMMEE
       vv..rreeccllaassss  - Creates a new map layer whose category values
       are based upon the user's reclassification  of  categories
       in  an  existing  vector map layer. (SCS GRASS Vector Pro-
       gram)

SSYYNNOOPPSSIISS
       vv..rreeccllaassss

       vv..rreeccllaassss hheellpp

       vv..rreeccllaassss [[--dd]] iinnppuutt_=_n_a_m_e oouuttppuutt_=_n_a_m_e ttyyppee_=_a_r_e_a_, _l_i_n_e_,  _o_r
       _s_i_t_e [ttiittllee_=_n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       _v_._r_e_c_l_a_s_s  creates  an  output map layer based on an input
       vector map layer.     The  output  map  layer  will  be	a
       reclassification  of  the input map layer based on reclass
       rules input to _v_._r_e_c_l_a_s_s.  A  title  for  the  output  map
       layer may be (optionally) specified by the user.


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

OOPPTTIIOONNSS
       The  user can run this program either non-interactively or
       interactively.  The program will be run	non-interactively
       if  the user specifies program arguments and flag settings
       on the command line using the form:


       _v_._r_e_c_l_a_s_s _[_-_d_] _i_n_p_u_t_=_n_a_m_e _o_u_t_p_u_t_=_n_a_m_e _t_y_p_e_=_a_r_e_a_,  _l_i_n_e_, _o_r
       _s_i_t_e _[_t_i_t_l_e_=_n_a_m_e_]


       After  the user types in the above information on the com-
       mand line, the program will (silently) prompt the user for
       reclass	rules  to be applied to the input map layer cate-
       gories.	The form of these rules is described  in  further
       detail  in  the	sections  on  non-interactive program use
       reclass rules and examples, below.

   FFllaagg::
       --dd     Dissolve common boundaries between areas


   PPaarraammeetteerrss::
       iinnppuutt==nnaammee
	      Vector input map name.

       oouuttppuutt==nnaammee
	      Vector output map name.

       ttyyppee==nnaammee
	      Select type of vector input file.   Options:  area,
	      line, site



       Alternately,  the  user	can  simply type _v_._r_e_c_l_a_s_s on the
       command line, without program arguments.   In  this  case,
       the  user  will be prompted for all needed inputs.  Before
       using _v_._r_e_c_l_a_s_s one must know the following:


       1      The new categories desired; and,	which  old  cate-
       gories fit into which new categories.


       2      The names of the new categories.

IINNTTEERRAACCTTIIVVEE PPRROOGGRRAAMM UUSSEE:: EEXXAAMMPPLLEE
       Suppose	we want to reclassify the vector map layer roads,
       consisting of five categories, into the	three  new  cate-
       gories:	paved  roads, unpaved roads, and railroad tracks.
       The user is asked whether  the  reclass	table  is  to  be
       established  with  each category value initially set to 0,
       or with each category  value  initially	set  to  its  own
       value.  A screen like that shown below then appears, list-
       ing the categories of the roads vector  map  layer  to  be
       reclassified  and  prompting the user for the new category
       values to be assigned them.


	       ENTER NEW CATEGORY NUMBERS FOR THESE CATEGORIES

	     OLD CATEGORY NAME	     OLD       NEW
					  NUM	    NUM
	     no data			  0	    0__
	     Hard Surface, 2 lanes	       1	 0__
	     Loose Surface, 1 lane	       2	 0__
	     Improved Dirt		  3	    0__
	     Unimproved Dirt Trail	       4	 0__
	     Railroad, single track	       5	 0__

	     AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
			(OR <Ctrl-C> TO CANCEL)

       In the following screen the new category values have  been
       entered	beside the appropriate old category names.  Cells
       assigned category values 2, 3, and 4 in the old vector map
       layer  are  now	assigned  the new category value 2 in the
       reclassed map; cell data  formerly  assigned  to  category
       value 5 in the old vector map map are now assigned the new
       category value 3 in the reclassed map.

	       ENTER NEW CATEGORY NUMBERS FOR THESE CATEGORIES

	     OLD CATEGORY NAME	     OLD       NEW
					  NUM	    NUM
	     no data			  0	    0__
	     Hard Surface, 2 lanes	       1	 1__
	     Loose Surface, 1 lane	       2	 2__
	     Improved Dirt		  3	    2__
	     Unimproved Dirt Trail	       4	 2__
	     Railroad, single track	       5	 3__

	     AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
			(OR <Ctrl-C> TO CANCEL)

       Hitting the  escape  key   will	bring  up  the	following
       screen,	which  prompts	the user to enter a new title and
       category label for the newly reclassed categories.

		ENTER NEW CATEGORY NAMES FOR THESE CATEGORIES

	      TITLE:  Roads Reclassified
		CAT	   NEW CATEGORY NAME
		NUM
		 0	   no data
		 1	   Paved Roads
		 2	   Unpaved Roads
		 3	   Railroad, single track

	      AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
		      (OR <Ctrl-C> TO CANCEL)

       Based  upon  the  information  supplied by the user in the
       above sample screens, the new output  map  and  supporting
       category files are created.

NNOONN--IINNTTEERRAACCTTIIVVEE PPRROOGGRRAAMM UUSSEE:: RREECCLLAASSSS RRUULLEESS
       In non-interactive program use, the names of an input map,
       output map, type of input map, and output  map  title  are
       given on the command line.  However, the reclass rules are
       still read from standard input (i.e., from  the	keyboard,
       redirected from a file, or piped through another program).


       Once the user has specified an  input  vector  map  layer,
       output  map  layer  name,  type	of  input  map layer, and
       (optionally) output map layer title by typing:


       _v_._r_e_c_l_a_s_s _[_-_d _] _i_n_p_u_t_=_n_a_m_e _o_u_t_p_u_t_=_n_a_m_e _t_y_p_e_=_a_r_e_a_, _l_i_n_e_, _o_r
       _s_i_t_e _[_t_i_t_l_e_=_n_a_m_e_]


       Each line of input must have the following format:


       _i_n_p_u_t___c_a_t_e_g_o_r_i_e_s_=_o_u_t_p_u_t___c_a_t_e_g_o_r_y _[_l_a_b_e_l_]


       where  the  input lines specify the category values in the
       input vector map layer to be reclassified to the new  out-
       put_category  category value.  Specification of a label to
       be associated with the new output map  layer  category  is
       optional.   If  specified,  it is recorded as the category
       label for the new category value.  The  equal  sign  =  is
       required.   The	input_category(ies) may consist of single
       category values or a range of such values  in  the  format
       "low thru high."  The word "thru" must be present.


       A  line containing only the word end terminates the input.

NNOONN--IINNTTEERRAACCTTIIVVEE PPRROOGGRRAAMM UUSSEE:: EEXXAAMMPPLLEESS
       The following examples may help clarify the reclass rules.


       1    This  example  reclassifies  categories 1, 3 and 5 in
       the input vector map layer to  category	1  with  category
       label  "poor quality" in the output map layer, and reclas-
       sifies input vector map layer categories 2, 4,  and  6  to
       category 2 with the label "good quality" in the output map
       layer.

		 1 3 5	 =  1	poor quality
		 2 4 6	 =  2	good quality

       2    This example  reclassifies	input  vector  map  layer
       categories 1 thru 10 to output map layer category 1, input
       map layer categories 11 thru 20 to output map layer  cate-
       gory  2, and input map layer categories 21 thru 30 to out-
       put map layer category 3, all without labels.

		  1 thru 10	  =   1
		 11 thru 20	  =   2
		 21 thru 30	  =   3

       3    Subsequent rules override previous rules.  Therefore,
       the below example reclassifies input vector map layer cat-
       egories 1 thru 19 and 51 thru 100 to  category  1  in  the
       output  map  layer,  input  vector map layer categories 20
       thru 24 and 26 thru 50 to the output map layer category 2,
       and input vector map layer category 25 to the output cate-
       gory 3.

		 1 thru 100	   =   1   poor quality
		 20 thru 50	   =   2   medium quality
		  25	 =   3	 good quality

       4    The previous example could also have been entered as:

		   1  thru  19	     51 thru 100   =   1     poor
       quality
		 20 thru 24	 26 thru  50	=    2	   medium
       quality
		      25	=   3	  good quality

       or as:

		  1 thru 19	    =	  1   poor quality
		 51 thru 100	=    1
		 20 thru 24	    =	  2
		 26 thru 50	    =	  2   medium quality
		  25	  =	3   good quality

       The  final  example  was  given to show how the labels are
       handled.  If a new category value appears in more than one
       rule  (as  is  the case with new category values 1 and 2),
       the last label which was specified becomes the  label  for
       that  category.	 In  this  case  the  labels are assigned
       exactly as in the two previous examples.

NNOOTTEESS
       The _v_._r_e_c_l_a_s_s program generates a new  vector  map  layer.
       The  _v_._s_u_p_p_o_r_t  program	will  have to be run on the newly
       created vector map layer to build topology.  The  dissolve
       _[_-_d_] option will work on only those areas which are of the
       same conversion category value.	If a map area  is  inside
       (island) a converted area and is NOT converted to the same
       value, its boundaries are output to the resultant map.

WWAARRNNIINNGG
       Category values which are not explicitly reclassified to a
       new value by the user will be reclassified to 0.

SSEEEE AALLSSOO
       _v_._s_u_p_p_o_r_t

AAUUTTHHOORRSS
       Paul H. Fukuhara, USDA SCS, NCG-GSS

       R. L. Glenn, USDA SCS, NHQ-CGIS

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_5 _$



