[GRASS-SVN] r41123 - grass/branches/develbranch_6/raster/r.proj.seg

[svn_grass at osgeo.org]

Author: hamish
Date: 2010-02-19 19:44:14 -0500 (Fri, 19 Feb 2010)
New Revision: 41123

Modified:
   grass/branches/develbranch_6/raster/r.proj.seg/description.html
Log:
document -g, -p; update proj4 url

Modified: grass/branches/develbranch_6/raster/r.proj.seg/description.html
===================================================================
--- grass/branches/develbranch_6/raster/r.proj.seg/description.html	2010-02-19 21:50:13 UTC (rev 41122)
+++ grass/branches/develbranch_6/raster/r.proj.seg/description.html	2010-02-20 00:44:14 UTC (rev 41123)
@@ -137,11 +137,23 @@
 <em>PROJ.4</em> co-ordinate system translation library.
 </p>
 
+
 <h2>NOTES</h2>
 
 To avoid excessive time consumption when reprojecting a map the region and 
 resolution of the target location should be set appropriately beforehand.
-A simple way to do this is to generate a vector "box" map of the region in  
+
+<p>
+A simple way to do this is to check the projected bounds of the input map
+inthe current location's projection using the <b>-p</b> flag. The  <b>-g</b>
+flag reports the same thing, but in a form which can be directly cut and
+pasted into a <em>g.region</em> command. After setting the region in that
+way you might check the cell resolution with "<em>g.region -p</em>" then
+snap it to a regular grid with <em>g.region</em>'s -a flag. E.g.
+<tt>g.region&nbsp;-a&nbsp;res=5 -p</tt>.
+
+<p>
+A more involved way to do this is to generate a vector "box" map of the region in  
 the source location using <em><a href="v.in.region.html">v.in.region</a></em>.
 This "box" map is then reprojected into the target location with
 <em><a href="v.proj.html">v.proj</a></em>.
@@ -158,16 +170,17 @@
 impossible) to find in projections other than latitude-longitude so results
 may be odd with trimming.
 
+
 <h2>REFERENCES</h2>
 
-[1] Evenden, G.I.  (1990) <a href="http://proj.maptools.org/">Cartographic projection procedures for
+[1] Evenden, G.I.  (1990) <a href="http://proj.osgeo.org">Cartographic projection procedures for
 the UNIX environment - a user's manual.</a>  USGS Open-File Report 90-284 (OF90-284.pdf)
 See also there: Interim Report and 2nd Interim Report on Release 4, Evenden 1994).
 <p>
 Richards, John A. (1993), Remote Sensing Digital Image Analysis,
 Springer-Verlag, Berlin, 2nd edition. 
 <p>
-<a href=http://proj.maptools.org/>PROJ.4</a>: Projection/datum support library.
+<a href="http://proj.osgeo.org">PROJ.4</a>: Projection/datum support library.
 <p>
 <b>Further reading</b>
 <ul>
@@ -193,6 +206,7 @@
 The 'gdalwarp' and 'gdal_translate' utilities are available from the 
 <a href="http://www.gdal.org">GDAL</a> project.
 
+
 <h2>AUTHORS</h2>
 
 Martin Schroeder, University of Heidelberg, Germany<p>
@@ -202,4 +216,5 @@
 <p>
 Datum tranformation support and cleanup by Paul Kelly
 
-<p><i>Last changed: $Date$</i>
+<p>
+<i>Last changed: $Date$</i>