v.rm.dangles(1) 	      Grass User's Manual	       v.rm.dangles(1)



NNAAMMEE
       vv..rrmm..ddaanngglleess - Remove lines of specified length from GRASS vector file.
       (GRASS Vector Program)

SSYYNNOOPPSSIISS
       vv..rrmm..ddaanngglleess

       vv..rrmm..ddaanngglleess hheellpp

       vv..rrmm..ddaanngglleess iinnppuutt==_n_a_m_e oouuttppuutt==_n_a_m_e [mmaaxxlleennggtthh==_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       _v_._r_m_._d_a_n_g_l_e_s removes lines from a binary vector file (input) which have
       a  length  less	than or equal to maxlength.  The length is computed as
       sum(sqrt(x^2+y^2)) for the entire length of the line in	the  units  of
       the  map.  Lines that have attached lines at BOTH ends are not removed,
       regardless of length.  (Note that nodes that  have  more  than  1  line
       attached  show  as  red	in  v.digit.  Nodes with a single line show as
       green.)


       Specifying maxlength of less than or equal 0 (default is  -1)  disables
       length  checking  and  only  lines with attached lines at both ends are
       output. Note that the lines at the ends of a string of  lines  will  be
       eliminated  because  they  have 2 lines attached at one node (endpoint)
       and only 1 line attached at  the  other	node.  For  example,  5  lines
       attached in a row would have the first and last line eliminated leaving
       3 lines when using maxlength = -1. Running v.rm.dangles maxlength =  -1
       again would remove 2 more lines, leaving 1 line in this example.


       See  v.build.polylines for building single lines from multiple attached
       lines.


       To remove small segments on the order of the  map  resolution  (from  a
       raster to vector conversion, for example) consider specifying maxlength
       to be slightly greater than sqrt(2) times the map resolution  (assuming
       the Easting and Northing resolutions are the same).


       The  input file is NOT changed. The input file is coppied to the output
       file with appropriate lines removed.


       This program is very simple.  It copies header information to  the  new
       map file but does not copy catagory or attribute information.



   PPaarraammeetteerrss::
       iinnppuutt==_n_a_m_e
	      Name of a binary vector file

       oouuttppuutt==_n_a_m_e
	      Name given to binary vector output file.

       mmaaxxlleennggtthh==_v_a_l_u_e
	      Threshold length for deleting lines. Default value is -1


SSEEEE AALLSSOO
       _v_._b_u_i_l_d_._p_o_l_y_l_i_n_e_s_, _v_._c_l_e_a_n_, _v_._d_i_g_i_t_, _v_._p_r_u_n_e_, _v_._s_p_a_g_, _v_._s_u_p_p_o_r_t


AAUUTTHHOORR
       J.Soimasuo

       Faculty of Forestry

       University of Joensuu, Finland


       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_3_/_0_2_/_0_5 _1_1_:_0_6_:_5_1 _$



GRASS 5.0						       v.rm.dangles(1)
