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



NNAAMMEE
       vv..ssppaagg  - Process spaghetti-digitized binary vector file.
       _(_G_R_A_S_S _V_e_c_t_o_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       vv..ssppaagg
       vv..ssppaagg hheellpp
       vv..ssppaagg [--iisspp] mmaapp==_n_a_m_e [tthhrreesshhoolldd==_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       This  program  will  fix vector data that were not digitized in correct
       GRASS vector format.  It will create a node at every line crossing, and
       will delete all hanging lines of length less than the specified thresh-
       old.

OOPPTTIIOONNSS
   FFllaagg::
       --ii     Only do identical line removal pass.

       --ss     Snap nodes.

       --pp     Prompt user for threshold value.


   PPaarraammeetteerrss::
       mmaapp==_n_a_m_e
	      Name of the binary vector file to be fixed.

       tthhrreesshhoolldd==_v_a_l_u_e
	      Node-snapping threshold value.


NNOOTTEESS
       The user must run _v_._s_u_p_p_o_r_t after running _v_._s_p_a_g to correct the	topol-
       ogy (_d_i_g___p_l_u_s) file.


       _v_._s_p_a_g  generally  deletes  many lines from the input vector map layer.
       Because deleted lines are not eliminated from a vector data (_d_i_g) file,
       but  are  only  marked  as  deleted, the user will probably wish to run
       _v_._c_l_e_a_n on the vector  file  after  running  _v_._s_p_a_g  to	eliminate  any
       deleted lines from the _d_i_g file and decrease its size.

BBUUGGSS
       This  program contains several known bugs.  It will sometimes get stuck
       in a loop in which it creates the same line over and  over  again.   It
       will  occasionally  create an incorrect line.  Users are strongly urged
       to back-up their vector data files before running this alpha version of
       _v_._s_p_a_g.


       Update Note:

       1/93:   For  GRASS  Release  4.1,  the  --ii flag has been added and bugs
       fixed.  It works better than the 4.0 release.

       6/00:  The --ss and --pp flags has been added.  One reason for loop	fixed,
       please report if you get into the loop after this date.

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_._r_m_d_u_p_, _v_._s_u_p_p_o_r_t


AAUUTTHHOORR
       Dave Gerdes, U.S.Army Construction Engineering Research Laboratory

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_3_/_0_8_/_2_0 _0_8_:_1_0_:_1_3 _$



GRASS 5.0							     v.spag(1)
