[GRASS-SVN] r71312 - in grass/trunk/vector: v.lidar.correction v.lidar.edgedetection v.surf.bspline

svn_grass at osgeo.org svn_grass at osgeo.org
Mon Jul 24 14:59:39 PDT 2017


Author: mmetz
Date: 2017-07-24 14:59:39 -0700 (Mon, 24 Jul 2017)
New Revision: 71312

Modified:
   grass/trunk/vector/v.lidar.correction/v.lidar.correction.html
   grass/trunk/vector/v.lidar.edgedetection/v.lidar.edgedetection.html
   grass/trunk/vector/v.surf.bspline/v.surf.bspline.html
Log:
vector lidar modules: explain units of ew_step and ns_step

Modified: grass/trunk/vector/v.lidar.correction/v.lidar.correction.html
===================================================================
--- grass/trunk/vector/v.lidar.correction/v.lidar.correction.html	2017-07-24 04:08:20 UTC (rev 71311)
+++ grass/trunk/vector/v.lidar.correction/v.lidar.correction.html	2017-07-24 21:59:39 UTC (rev 71312)
@@ -24,6 +24,11 @@
     interpolated surface are interpreted and reclassified as TERRAIN, for
     both single and double pulse points.
 
+<p>
+The length (in mapping units) of each spline step is defined by 
+<b>ew_step</b> for the east-west direction and <b>ns_step</b> for the 
+north-south direction.
+
 <h2>NOTES</h2>
 
 The input should be the output of <em>v.lidar.growing</em> module or the 

Modified: grass/trunk/vector/v.lidar.edgedetection/v.lidar.edgedetection.html
===================================================================
--- grass/trunk/vector/v.lidar.edgedetection/v.lidar.edgedetection.html	2017-07-24 04:08:20 UTC (rev 71311)
+++ grass/trunk/vector/v.lidar.edgedetection/v.lidar.edgedetection.html	2017-07-24 21:59:39 UTC (rev 71312)
@@ -28,6 +28,11 @@
 threshold. Other points are classified as TERRAIN.
 
 <p>
+The length (in mapping units) of each spline step is defined by 
+<b>ew_step</b> for the east-west direction and <b>ns_step</b> for the 
+north-south direction.
+
+<p>
 The output will be a vector map in which points has been classified as 
 TERRAIN, EDGE or UNKNOWN. This vector map should be the input of 
 <em><a href="v.lidar.growing.html">v.lidar.growing</a></em> module.

Modified: grass/trunk/vector/v.surf.bspline/v.surf.bspline.html
===================================================================
--- grass/trunk/vector/v.surf.bspline/v.surf.bspline.html	2017-07-24 04:08:20 UTC (rev 71311)
+++ grass/trunk/vector/v.surf.bspline/v.surf.bspline.html	2017-07-24 21:59:39 UTC (rev 71312)
@@ -11,21 +11,22 @@
 
 <h2>NOTES</h2>
 
-<p>From a theoretical perspective, the interpolating procedure takes
-place in two parts: the first is an estimate of the linear
-coefficients of a spline function is derived from the observation
-points using a least squares regression; the second is the computation
-of the interpolated surface (or interpolated vector points). As used
-here, the splines are 2D piece-wise non-zero polynomial functions
-calculated within a limited, 2D area. The length of each spline step
-is defined by <b>ew_step</b> for the east-west direction and
-<b>ns_step</b> for the north-south direction. Step is defined in number of 
-pixels. For optimal performance, the length of spline step should be no less
-than the distance between observation points. Each vector point observation is
-modeled as a linear function of the non-zero splines in the area around the 
-observation. The least squares regression predicts the the coefficients of these
-linear functions. Regularization, avoids the need to have one observation and 
-one coefficient for each spline (in order to avoid instability). 
+<p>From a theoretical perspective, the interpolating procedure takes 
+place in two parts: the first is an estimate of the linear coefficients 
+of a spline function is derived from the observation points using a 
+least squares regression; the second is the computation of the 
+interpolated surface (or interpolated vector points). As used here, the 
+splines are 2D piece-wise non-zero polynomial functions calculated 
+within a limited, 2D area. The length (in mapping units) of each spline 
+step is defined by <b>ew_step</b> for the east-west direction and 
+<b>ns_step</b> for the north-south direction. For optimal performance, 
+the length of spline step should be no less than the distance between 
+observation points. Each vector point observation is modeled as a 
+linear function of the non-zero splines in the area around the 
+observation. The least squares regression predicts the the coefficients 
+of these linear functions. Regularization, avoids the need to have one 
+observation and one coefficient for each spline (in order to avoid 
+instability). 
 
 <p>With regularly distributed data points, a spline step corresponding
 to the maximum distance between two points in both the east and north



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