Circle generation

[Michael Shapiro]

There was in GRASS3.0 (or earlier) a module called mapmask  which
made  circles  and  polygonal  shapes that was never converted to
GRASS4.0. Someone somewhere made a decision to not  convert  this
module  since  it  seemed  like  duplication. Plus it didn't make
vector maps, just raster maps. The only  way  to  make cirles is
interactively using r.digit (which isn't in 4.0 but is on the ftp
site) using the mouse to define the center and the  radius.  This
also  only  generates  raster maps.  I don't think there was ever
tool to generate a vector circle.

r.digit uses an new program r.in.poly to create  the  raster  map
(also  not  in  4.0  but on the ftp as well). It only knows about
lines and polgons.  If someone wanted  to  upgrade  r.in.poly  to
know  about  cirlces  or  ellipses or whatever and contribute the
upgrade back into GRASS ....

|
|Help,
|
|I thought that in GRASS3.0 there was a module where you could
|generate a circle (in vector form) by specifying an x,y location
|and the radius of the circle.  I cannot seem to accomplish this
|task easily within GRASS4.0.  I can get a vector circle by 
|specifying a site location, converting to a raster map, then 
|using r.buffer and finally r.poly.  I am certain that I did it 
|much easier before, but cannot find the module to do it in 4.0.
|
|I tried d.mapgraph but cannot get circle, only point defined polygons.
|Besides, these graphics appear to only be graphics, I want to save
|the circles as a vector file for later use.
|
|I imagine I have just over-looked something and would greatly 
|appreciate any insight anyone could provide.
|
|Thanks in advance.
|
|Mark
|
|


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Michael Shapiro                        U.S. Army CERL                  
email:   shapiro at amber.cecer.army.mil  Office of GRASS Integration
phone:   (217) 373-7277                P.O. Box 9005                   
fax:     (217) 373-7222                Champaign, Ill. 61826-9005
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