Creating cirles from sites

[Alejandro Hinojosa Corona]

> One of our offices is interested in created circular zones around
> sharptail grouse habitat sites.  They need a GRASS routine for
> making a circular vector from a site file.  I seem to remember
> seeing talk about a v.circle or an s.circle some time in the past.
> Is there such a program?

 David ,

I am including some OLD refernces to v.circle gathered
from my emails. Hope You can find it.

Regards

Alejandro Hinojosa
Research Associate
Earth Sciences Division
CICESE 
Ensenada, Baja California, Mexico. 
-----------------------Begining of references-----------

From: nps!bruce at cerl.cecer.army.mil (Bruce Powell)

NPS (National Park Service) has produced three GRASS programs.  These three
programs are:

     v.circle - Creates one or more "polygon" circles in a binary
     vector file.  These circles are created using each point
     from an existing "site_lists" file as the centers for those
     circles.  There is one circle created per "site_lists"
     point.
     (GRASS Vector Program)

 If you would like information concerning these programs, please contact:
Bruce Powell, NPS, 303 969 2590.

.........
-------------------------------------------------------
From: susan at nps.gov (Susan Stitt)


you can find the source code for v.circle in src.contrib/NPS

Susan Stitt   National Biological Survey     sstitt at its.nbs.gov
---------------------------------------------------------

From: nps!bruce at cerl.cecer.army.mil (Bruce Powell)

Manual pages for "v.circle", "r.in.elas", and "r.out.elas":


v.circle             GRASS Reference Manual              v.circle



NAME
     v.circle - Creates one or more "polygon" circles in a binary
     vector file.  These circles are created using each point
     from an existing "site_lists" file as the centers for those
     circles.  There is one circle created per "site_lists"
     point.
     (GRASS Vector Program)

SYNOPSIS
     v.circle
     v.circle help
     v.circle [-s] [radius=value] [radius_uom=name] [area=value]
        [area_uom=name] sitefile=name output=name


DESCRIPTION
     "v.circle" will create a vector "polygon" circle around each
     point read from an existing "site_lists" file.  Each
     "site_lists" point will be the center for each circle with
     one circle created per point.  The "polygon" circle will be
     written to a binary vector file.  Each "polygon" circle will
     have 361 points with each point on the circumference of the
     circle representing 1 degree of arc.  "v.circle" only
     creates vector files of either unreferenced XY or UTM
     projections.  If you use the unreferenced XY projection then
     the coordinates are assumed to be in meters.  The
     coordinates for the vector file outputted will always be in
     meters irregardless of whether you use the unreferenced XY
     or UTM projections.


COMMAND LINE OPTIONS
     Flags

     -s   Automatically run "v.support" on newly created vector
          file.

     Parameters

     radius
          Radius of circle(s) with "site_lists" point(s) as
          center(s).  If radius selected then area values are not
          used for computations.  If both radius and area
          selected, then radius has precedence over area.
          default: 0.0

     radius_uom
          Radius unit of measure,  i.e. (m)meters,  ft(feet),
          (mi)miles.
          default: m

     area Area of circle(s) with "site_lists" point(s) as



GRASS 4.0                U.S. Army CERL                         1






v.circle             GRASS Reference Manual              v.circle



          center(s).
           If area selected then radius values are not used for
          computations.
          default: 0.0

     area_uom
          Area unit of measure,  i.e. sqm(square meters),
          ac(acres),  sqmi(square miles),  hec(hectares).
          default: sqm

     sitefile
          GRASS site_lists file (input).

     output
          Vector file to be created (output).


AUTHOR
     Bruce Powell, National Park Service