[GRASS-SVN] r70627 - grass/trunk/vector/v.distance
svn_grass at osgeo.org
svn_grass at osgeo.org
Sun Feb 19 13:47:27 PST 2017
Author: hcho
Date: 2017-02-19 13:47:27 -0800 (Sun, 19 Feb 2017)
New Revision: 70627
Modified:
grass/trunk/vector/v.distance/local_proto.h
grass/trunk/vector/v.distance/print.c
grass/trunk/vector/v.distance/v.distance.html
Log:
v.distance: Add an example for table= without -a
Modified: grass/trunk/vector/v.distance/local_proto.h
===================================================================
--- grass/trunk/vector/v.distance/local_proto.h 2017-02-19 21:28:50 UTC (rev 70626)
+++ grass/trunk/vector/v.distance/local_proto.h 2017-02-19 21:47:27 UTC (rev 70627)
@@ -50,7 +50,7 @@
int cmp_exist(const void *, const void *);
/* distance.c */
-int get_line_box(const struct line_pnts *Points,
+int get_line_box(const struct line_pnts *Points,
struct bound_box *box);
int line2line(struct line_pnts *FPoints, int ftype,
struct line_pnts *TPoints, int ttype,
Modified: grass/trunk/vector/v.distance/print.c
===================================================================
--- grass/trunk/vector/v.distance/print.c 2017-02-19 21:28:50 UTC (rev 70626)
+++ grass/trunk/vector/v.distance/print.c 2017-02-19 21:47:27 UTC (rev 70627)
@@ -1,7 +1,7 @@
#include "local_proto.h"
/*
- print out upload values
+ print out upload values
*/
int print_upload(NEAR * Near, UPLOAD * Upload, int i,
dbCatValArray * cvarr, dbCatVal * catval, char *sep)
Modified: grass/trunk/vector/v.distance/v.distance.html
===================================================================
--- grass/trunk/vector/v.distance/v.distance.html 2017-02-19 21:28:50 UTC (rev 70626)
+++ grass/trunk/vector/v.distance/v.distance.html 2017-02-19 21:47:27 UTC (rev 70627)
@@ -1,29 +1,29 @@
<h2>DESCRIPTION</h2>
-<em>v.distance</em> finds the nearest element in vector map (<b>to</b>)
-for elements in vector map (<b>from</b>). Various information about
-the vectors' relationships (distance, category, etc.) may be uploaded to
-the attribute table attached to the first vector map, or printed to
-'stdout'. A new vector map may be created where lines connecting
-nearest points on features are written. <b>dmin</b> and/or
+<em>v.distance</em> finds the nearest element in vector map (<b>to</b>)
+for elements in vector map (<b>from</b>). Various information about
+the vectors' relationships (distance, category, etc.) may be uploaded to
+the attribute table attached to the first vector map, or printed to
+'stdout'. A new vector map may be created where lines connecting
+nearest points on features are written. <b>dmin</b> and/or
<b>dmax</b> can be used to limit the search radius (in lat-long locations
to be given in meters since they are calculated as geodesic distances on
a sphere).
<p>
-For lines to lines, say line A to line B, <em>v.distance</em> calculates
-the shortest distance of each vertex in A with each segment (not vertex)
-in B. The module then calculates the shortest distance of each vertex in
-B to each segment in A. The overall shortest distance of A points to B
-segments and B points to A segments is used. Additionally,
+For lines to lines, say line A to line B, <em>v.distance</em> calculates
+the shortest distance of each vertex in A with each segment (not vertex)
+in B. The module then calculates the shortest distance of each vertex in
+B to each segment in A. The overall shortest distance of A points to B
+segments and B points to A segments is used. Additionally,
<em>v.distance</em> checks for intersections. In case of intersections,
the first intersection found is used and the distance set to zero.
<p>
-For lines to areas, the distance is set to zero if a line is (partially)
-inside an area. The first point of the line that is inside the area is
-used as common point. The distance is also set to zero if the line
-intersects with the outer ring or any of the inner rings (isles), in
+For lines to areas, the distance is set to zero if a line is (partially)
+inside an area. The first point of the line that is inside the area is
+used as common point. The distance is also set to zero if the line
+intersects with the outer ring or any of the inner rings (isles), in
which case the fist intersection is used as common point.
<p>
@@ -36,7 +36,7 @@
<p>
For anything else than points to lines, there can be several common
-locations with zero distance, and the common location would then be the
+locations with zero distance, and the common location would then be the
result of an overlay consisting of several points, lines, or areas.
<em>v.distance</em> selects in these cases a single point, and does
not create an overlay
@@ -50,14 +50,14 @@
<h2>NOTES</h2>
-If a nearest feature does not have a category, the attribute column is
+If a nearest feature does not have a category, the attribute column is
updated to NULL.
-<p>The upload <b>column</b>(s) must already exist. Create one with
+<p>The upload <b>column</b>(s) must already exist. Create one with
<em><a href="v.db.addcolumn.html">v.db.addcolumn</a></em>.
-<p>In lat-long locations <em>v.distance</em> gives distances
-(<em>dist</em>, <em>from_along</em>, and <em>to_along</em>) not in
+<p>In lat-long locations <em>v.distance</em> gives distances
+(<em>dist</em>, <em>from_along</em>, and <em>to_along</em>) not in
degrees but in meters calculated as geodesic distances on a sphere.
<p>
@@ -100,6 +100,17 @@
v.distance from=pnt to=ln out=connections upload=dist column=dist
</pre></div>
+<h3>Create a new vector map with from and to categories in the attribute table</h3>
+
+Create a new vector map that contains <em>lines connecting nearest
+features</em> of maps "pnt" and map "ln", and a new
+attribute table that contains distances, from and to categories from the
+input maps:
+
+<div class="code"><pre>
+v.distance from=pnt to=ln out=connections upload=cat,dist column=to_cat,dist table=connections
+</pre></div>
+
<h3>Query information</h3>
Query information from selected point(s). <em>v.distance</em> takes
@@ -194,7 +205,7 @@
<div class="code"><pre>
v.distance -pa from=hospitals to=hospitals upload=dist separator=tab
-from_cat to_cat dist
+from_cat to_cat dist
1 2 3 4 5 ...
1 0 7489.10 339112.17 70900.39 70406.23 ...
2 7489.10 0 345749.12 76025.46 75538.87 ...
@@ -221,7 +232,8 @@
Updated for 5.1: Radim Blazek, ITC-irst, Trento, Italy<br>
Matrix-like output by Martin Landa, FBK-irst, Trento, Italy<br>
Improved processing speed: Markus Metz<br>
-Distance from any feature to any feature: Markus Metz
+Distance from any feature to any feature: Markus Metz<br>
+New table without the -p flag: Huidae Cho
<p>
<i>Last changed: $Date$</i>
More information about the grass-commit
mailing list