v.in.poly(1)		      Grass User's Manual		  v.in.poly(1)



NNAAMMEE
       vv..iinn..ppoollyy   -  Create a vector file of polygons centered on given loca-
       tions
       _(_G_R_A_S_S _V_e_c_t_o_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       vv..iinn..ppoollyy
       vv..iinn..ppoollyy hheellpp
       vv..iinn..ppoollyy [ --tt] [iinnppuutt==_n_a_m_e] vveecctt==_n_a_m_e rraaddiiuuss==_v_a_l_u_e [sseeggmmeennttss==_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       This program creates a vector  map  of  polygons  of  specified	radius
       around center points which may be input as coordinate pairs from a file
       or from stdin.

CCOOMMMMAANNDD LLIINNEE OOPPTTIIOONNSS
       FFllaaggss



       --tt     Do not automatically build topology for the new map


       PPaarraammeetteerrss



       iinnppuutt==_n_a_m_e
	      Name of input file (omit or use - for input from stdin)
	      default: - (stdin)

       vveecctt==_n_a_m_e
	      Name of new vector map to create

       rraaddiiuuss==_v_a_l_u_e
	      Radius of polygon's circumscribed circle
	      default: none

       sseeggmmeennttss==_v_a_l_u_e
	      Number of straight line segments bounding the polygon
	      default: set to give perimeter point spacing  of	0.02%  of  the
	      width  of  the  current  region  based on the radius given.  The
	      smallest number of segments that will be automatically  used  is
	      six(6).  Values down to 3 may be explicitly selected on the com-
	      mand line or in input lines (see below).	A value of  3  results
	      in an equilateral triangle, 4 a square, etc.



DDIISSCCUUSSSSIIOONN AANNDD AADDDDIITTIIOONNAALL IINNPPUUTT LLIINNEE PPAARRAAMMEETTEERRSS
       If  input  is  from  a  keyboard, a prompt will be given for each input
       line.  The input lines from the file or stdin should look like this:


	 easting northing [label] [category desc]
		     or
	 easting northing [#label] [category desc]


       The "#label" for is for center  points  piped  from  s.out.ascii,  like
       this:

	 ss..oouutt..aasscciiii --dd  sitefile | vv..iinn..ppoollyy vveecctt==newvect rraaddiiuuss==500

       The  polygon  (area)  label  and  category  description	are  optional.
       "label" is an integer and the "category desc" is any text  string.   If
       the  label  value  is missing, the label value used is one greater than
       the last and the description is "n-sided polygon," where n is the  num-
       ber  of	bounding  segments.  In this way a series of sequentially num-
       bered polygons may be created by just giving the easting  and  northing
       center coordinates.


       Two  optional  command  lines  may be interspersed with the input lines
       containing the coordinate and optional label and category descriptions.
       These  lines  begin with ".S" or ".R".  Note the restrictions on values
       of radius and segments parameters below.


	.S 500


       Changes the number of straight line segments which bound the polygon to
       a  new  value.	With  large values (greater than 20) the polygons will
       approximate circles.  The minimum value of 3 will create an equilateral
       triangle.   Very  large values are allowed, but the resulting "circles"
       may have more definition than is needed and will take lots  of  storage
       space for the vector map.


	.R 100


       Changes	the  radius  of  the  circle  to  a new value.	Radius must be
       greater than 0.0; however, very small values may give meaningless  cir-
       cles  and  v.support  may  not be able to construct the topology if the
       points on the perimeter are too closely spaced.



BBUUGGSS
       Circles in Lat-Long locations are not really round.  Really large  Lat-
       Long circles or polygons may look oddly misshappen when displayed.



SSEEEE AALLSSOO
       _v_._t_o_._r_a_s_t  can be used to convert the polygons to raster maps for mask-
       ing, etc.



AAUUTTHHOORR
       Dr. James R. Hinthorne, GIS Laboratory, Central Washington  University.
       April 1992.

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



GRASS 5.0							  v.in.poly(1)
