[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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