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



NNAAMMEE
       vv..iinn..ttrraannsseeccttss  - import transect data to a GRASS vector map
       _(_G_R_A_S_S _V_e_c_t_o_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       vv..iinn..ttrraannsseeccttss
       vv..iinn..ttrraannsseeccttss hheellpp

       vv..iinn..ttrraannsseeccttss [--aa] iinnppuutt==_n_a_m_e
	      [ffss==_c_h_a_r_a_c_t_e_r"]  lleennggtthh==_v_a_l_u_e [uunniittss==_n_a_m_e] [ddeeccll==_n_a_m_e] vveecctt==_n_a_m_e
	      [TTIITTLLEE==_n_a_m_e"]




DDEESSCCRRIIPPTTIIOONN
       vv..iinn..ttrraannsseeccttss imports "transects" into a GRASS vector map. A  transect
       is  a  line (or an area) which is described by a starting coordinate, a
       direction or azimuth, (or backward, forward,  rightside,  and  leftside
       distances  from	the  line transect), and a length (in meters or feet).
       The information describing the transects must be in a file prepared  by
       the  user  before  running  vv..iinn..ttrraannsseeccttss..  The format of this file is
       described below in the section ""TTRRAANNSSEECCTT FFIILLEE FFOORRMMAATT""..



OOPPTTIIOONNSS
   FFllaaggss::
       --aa     Run for area transects. Default is line  transects,  i.e.,  this
	      flag is not used.






   PPaarraammeetteerrss::
       iinnppuutt  transect information file


       This  is  the  file containing the transect information to be imported.
       The format of this file is described below  in  the  section  ""TTRRAANNSSEECCTT
       FFIILLEE FFOORRMMAATT""

       ffss     input data field separator


       The  transect  file  is organized one transect per line with at least 4
       fields.	The _f_s option specifies the character  that  is  used  in  the
       transect  information  file  to	separate the fields. If not specified,
       fields are assumed to be separated by blanks (white space). (Quote  the
       delimeter  whenever  you are not sure whether it has special meaning in
       UNIX or not, to avoid the misunderstanding by GRASS.)

       lleennggtthh transect length


       This is the length of the transects (default is in  grid  units,  e.g.,
       meters).   It  is  assumed  that all transects have the same length. If
       they do not, then more than one import process must be  run  to	create
       two  or	more  vector  files  and  the  results patched together (using
       v.patch ).

       uunniittss  units of the length
	      default: meter


       This is the unit of the transect. It can be meter or foot.

       ddeeccll   declination - angle (in degrees) to be added  to	input  azimuth
	      angles
	      default: 0


       Each  transect has a direction or azimuth angle associated with it. The
       map projection may have a declination associated with  it  and  if  the
       azimuth	angles	embedded in the transect input file do not account for
       this declination, it may be specified here.

       vveecctt   Vector map to be created

       TTIITTLLEE  Title for resultant vector map
	      default: Transect map


       If TITLE is more than one word, it should always be quoted.




TTRRAANNSSEECCTT FFIILLEE FFOORRMMAATT
       The format for the transect file consists of one  record  or  line  per
       transect  with  4  mandatory  fields  and a 5th optional field for line
       transects. The first field is the GRASS category number to be  assigned
       to  the transect.  The second and third fields are the easting and nor-
       thing (respectively) of the starting coordinate for the transect.   The
       fourth  field  is  the  azimuth	in degrees clockwise from north of the
       transect.  Following the fourth field is an optional fifth  field  that
       is the category label for the transect. The following is a simple exam-
       ple with 3 transects:



       1 709818   5453991   246.0   P CLGR 4 73 1 21 0 0 0 0 1
       2 698350   5464162   128.0   P CLGR 0 55 0 36 0 0 0 0 1
       3 704615   5461874   190.5   P DEGR 0 34 4 15 0 0 0 0 0

       Note that the fifth field (i.e., the label) is really everything  after
       the azimuth, not just the P.


       This file could be formatted as follows:



       1:709818:5453991:246.0:P:CLGR:4:73:1:21:0:0:0:0:1
       2:698350:5464162:128.0:P:CLGR:0:55:0:36:0:0:0:0:1
       3:704615:5461874:190.5:P:DEGR:0:34:4:15:0:0:0:0:0

       In this case the fields are separated by a colon so _f_s_=_: must be speci-
       fied on the command line. The labels (starting with the P) would retain
       the  colons (i.e., they are not removed from the label even though they
       act to define the first 4 fields).




       When area transects are required, the  transects  file  should  include
       four  (4)  more	fields	for backward, forward, rightside, and leftside
       distance from the corresponding line transect. The format  will	be  as
       the following:



       1    709818   5453991   246.0   10.0   15.0   20.0    5.0   P CLGR 4 73
       1 21 0 0 0 0 1
       2   698350   5464162   128.0    5.0   15.0   10.0   25.0   P CLGR 0  55
       0 36 0 0 0 0 1
       3    704615   5461874   190.5   15.0   20.0   10.0    5.0   P DEGR 0 34
       4 15 0 0 0 0 0

       Note that delimiter could be other than white space in  transect  file.
       Vector  files  of  line	transects can be generated from the above area
       transects file by not using _-_a flag. However, the  label  will  include
       four (4) more items.





NNOOTTEESS
       The resulting vector map is a complete GRASS vector map: it will have a
       category file with the labels from the input file and it will have  the
       topology  file  already	built.	 (  v.support  is run automatically by
       vv..iinn..ttrraannsseeccttss as the final step in creating the GRASS vector map.)



AAUUTTHHOORRSS
       Tao Wen, University of Illinois at Urbana-Champaign, Illinois.
       Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

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



GRASS 5.0						     v.in.transects(1)
