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



NNAAMMEE
       _r_._c_o_n_t_o_u_r  -  Produces  a GRASS binary vector map of specified contours
       from GRASS raster map layer.

       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..ccoonnttoouurr

       rr..ccoonnttoouurr hheellpp

       rr..ccoonnttoouurr [[--qqnn]] iinnppuutt==_n_a_m_e  oouuttppuutt==_n_a_m_e	[lleevveellss==_v_a_l_u_e,_v_a_l_u_e,...,_v_a_l_u_e]
       [mmiinnlleevveell==_v_a_l_u_e] [mmaaxxlleevveell==_v_a_l_u_e] [sstteepp==_v_a_l_u_e] [ccuutt==_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       _r_._c_o_n_t_o_u_r produces a contour map of user-specified levels from a raster
       map layer. This program works two ways:

	      Contours are produced from a user-specified list of levels.

	      Contours are produced at some regular increment from user-speci-
	      fied  minimum  level  to maximum level. If no minimum or maximum
	      level is specified, minimum or maximum data value will be  used.


OOPPTTIIOONNSS
       _r_._c_o_n_t_o_u_r  may  be  run	interactively or non-interactively. To run the
       program non-interactively, the user must specify the input  and	output
       file  names,  either  a list of levels or a step value and, optionally,
       minimum and maximum  levels:  rr..ccoonnttoouurr	[[--qqnn]]  iinnppuutt==_n_a_m_e  oouuttppuutt==_n_a_m_e
       [lleevveellss==_v_a_l_u_e,_v_a_l_u_e,...,_v_a_l_u_e]	  [mmiinnlleevveell==_v_a_l_u_e]    [mmaaxxlleevveell==_v_a_l_u_e]
       [sstteepp==_v_a_l_u_e] [ccuutt==_v_a_l_u_e]

       To run the program interactively, the user may simply type rr..ccoonnttoouurr at
       the command line and will be prompted for parameter values.



   FFllaaggss::
       --qq   Suppress progress report & min/max information

       --nn   Suppress single crossing error messages

   PPaarraammeetteerrss::
       iinnppuutt==_n_a_m_e
	   Name of input raster map layer.

       oouuttppuutt==_n_a_m_e
	   Name of the binary vector file created.

       lleevveellss==_v_a_l_u_e,_v_a_l_u_e,...,_v_a_l_u_e
	   Comma separated list of desired levels.

       mmiinnlleevveell==_v_a_l_u_e
	   Beginning (lowest) value to be used when stepping through contours.
	   Default is minimum data value.

       mmaaxxlleevveell==_v_a_l_u_e
	   Ending (highest) value to be used when stepping  through  contours.
	   Default is maximum data value.

       sstteepp==_v_a_l_u_e
	   Increment between contour levels.

       ccuutt==_v_a_l_u_e
	   Minimum  number  of	points	for  a	contour  line  (0 -> no limit,
	   default: 0)


NNOOTTEESS
       _r_._c_o_n_t_o_u_r will either step through incremental contours or produce con-
       tours  from  a list of levels, not both. If both a list of levels and a
       step are specified, the list will be produced  and  the	step  will  be
       ignored.

       Zero is treated as a valid data value by _r_._c_o_n_t_o_u_r.

       If a contour level exactly matches a category value in the raster file,
       the contour line may backtrack on itself, causing illegal  arcs	to  be
       produced in the output GRASS vector file.

       The  optional _c_u_t parameter allows to specify a minimum number of point
       for a contour line to be put into output  vector  map,  so  that  small
       spurs,  single points and so on won't be present and the output will be
       more clear.

AAUUTTHHOORRSS
       Terry Baker, U.S. Army Construction Engineering Research Laboratory

       3/2001: cut parameter and fixes by Andrea Aime (aaime@libero.it)

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_4 _$



GRASS 5.0							  r.contour(1)
