[GRASS-SVN] r64178 - grass/branches/releasebranch_7_0/raster/r.slope.aspect
svn_grass at osgeo.org
svn_grass at osgeo.org
Wed Jan 14 07:35:10 PST 2015
Author: annakrat
Date: 2015-01-14 07:35:10 -0800 (Wed, 14 Jan 2015)
New Revision: 64178
Modified:
grass/branches/releasebranch_7_0/raster/r.slope.aspect/main.c
grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html
Log:
r.slope.aspect: change behavior for locations where units are not meters #2536 (merge from trunk, r64177)
Modified: grass/branches/releasebranch_7_0/raster/r.slope.aspect/main.c
===================================================================
--- grass/branches/releasebranch_7_0/raster/r.slope.aspect/main.c 2015-01-14 15:32:16 UTC (rev 64177)
+++ grass/branches/releasebranch_7_0/raster/r.slope.aspect/main.c 2015-01-14 15:35:10 UTC (rev 64178)
@@ -241,7 +241,7 @@
parm.zfactor = G_define_option();
parm.zfactor->key = "zscale";
parm.zfactor->description =
- _("Multiplicative factor to convert elevation units to meters");
+ _("Multiplicative factor to convert elevation units to horizontal units");
parm.zfactor->type = TYPE_DOUBLE;
parm.zfactor->required = NO;
parm.zfactor->answer = "1.0";
@@ -382,10 +382,11 @@
/* V = window.ns_res * 4 * 2/ zfactor; *//* vertical (north-south) run
times 4 for weighted difference */
- /* give warning if location units are different from meters and zfactor=1 */
+ /* we don't assume vertical units to be meters any more */
factor = G_database_units_to_meters_factor();
- if (factor != 1.0)
- G_warning(_("Converting units to meters, factor=%.6f"), factor);
+ if (factor != 1.0 && zfactor != 1.0)
+ G_warning(_("r.slope.aspect does not convert horizontal units "
+ "to meters in this version, see manual page."));
G_begin_distance_calculations();
north = Rast_row_to_northing(0.5, &window);
@@ -393,8 +394,8 @@
south = Rast_row_to_northing(2.5, &window);
east = Rast_col_to_easting(2.5, &window);
west = Rast_col_to_easting(0.5, &window);
- V = G_distance(east, north, east, south) * 4 / zfactor;
- H = G_distance(east, ns_med, west, ns_med) * 4 / zfactor;
+ V = G_distance(east, north, east, south) * 4 / (factor * zfactor);
+ H = G_distance(east, ns_med, west, ns_med) * 4 / (factor * zfactor);
/* ____________________________
|c1 |c2 |c3 |
| | | |
@@ -551,8 +552,8 @@
south = Rast_row_to_northing((row + 0.5), &window);
east = Rast_col_to_easting(2.5, &window);
west = Rast_col_to_easting(0.5, &window);
- V = G_distance(east, north, east, south) * 4 / zfactor;
- H = G_distance(east, ns_med, west, ns_med) * 4 / zfactor;
+ V = G_distance(east, north, east, south) * 4 / (factor * zfactor);
+ H = G_distance(east, ns_med, west, ns_med) * 4 / (factor * zfactor);
/* ____________________________
|c1 |c2 |c3 |
| | | |
Modified: grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html
===================================================================
--- grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html 2015-01-14 15:32:16 UTC (rev 64177)
+++ grass/branches/releasebranch_7_0/raster/r.slope.aspect/r.slope.aspect.html 2015-01-14 15:35:10 UTC (rev 64178)
@@ -5,15 +5,17 @@
elevation values. The user must specify the input <b>elevation</b> raster map
and at least one output raster maps. The user can also specify the
<b>format</b> for slope (degrees, percent; default=degrees), and the
-<b>zscale</b>: multiplicative factor to convert elevation units to meters;
+<b>zscale</b>: multiplicative factor to convert elevation units to horizontal units;
(default 1.0).
<p>
The <b>elevation</b> input raster map specified by the user must contain true
elevation values, <em>not</em> rescaled or categorized data. If the elevation
-values are in feet or other units than meters (with a conversion factor
-<i>meters:</i>, defined in PROJ_UNITS), they must be converted to meters using
-the parameter <b>zscale</b>.
+values are in other units than in the horizontal units,
+they must be converted to horizontal units using the parameter <b>zscale</b>.
+<em>In GRASS GIS 7, vertical units are not assumed to be meters any more.
+For example, if both your vertical and horizontal units are feet,
+parameter <b>zscale</b> must not be used</em>.
<p>
The <b>aspect</b> output raster map indicates the direction that slopes are
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