1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
<H2>DESCRIPTION</H2>
<EM>v.sample</EM> samples a GRASS raster map at the point
locations in the input file by either cubic convolution
interpolation, bilinear interpolation, or nearest neighbor
sampling (default).
<P>
This program may be especially useful when sampling for
cross validation of interpolations whose output is a raster
map.
<H2>NOTES</H2>
<P>
The output points will have the easting and northing of the input points.
The input category value is used. The input attribute, raster value
and difference is written to output.
<P>
<P>
When NULL values are encountered for a cell, zero value is used
instead. In these cases, more acurrate results may be obtained
by using the default nearest neighbor comparisons.
<P>
This program may not work properly with lat-long data when
the <B>-BC</B> flags are used.
<P>
When interpolation is done (i.e., the <B>-BC</B> flags are
used), values are assumed to be located at the centroid of
grid cells. Therefore, current resolution settings are
important.
<H2>SEE ALSO</H2>
<EM><A HREF="v.random.html">s.random</A></EM><br>
<EM><A HREF="g.region.html">g.region</A></EM><br>
<EM>Image Sampling Methods</EM> - GRASS Tutorial on <EM>s.sample</EM>
(available as
<A HREF="../../sites/">s.sample-tutorial.ps.gz</A>)
<H2>BUGS</H2>
Please send all bug fixes and comments to the author
or the grass development team. <br>
<a href="http://grass.itc.it"><tt>http://grass.itc.it</tt></A>
<H2>AUTHOR</H2>
<A HREF="http://mccauley-usa.com/">James Darrell McCauley</A>
<A HREF="mailto:darrell@mccauley-usa.com"><darrell@mccauley-usa.com></A>,
<br>when he was at:
<A HREF="http://ABE.www.ecn.purdue.edu/ABE/">Agricultural
Engineering</A>
<A HREF="http://www.purdue.edu/">Purdue University</A>
<P>
Updated for GRASS 5.0 by Eric G. Miller
<BR>
Updated for GRASS 5.7 by Radim Blazek
<p><i>Last changed: $Date: 2005/02/03 10:59:51 $</i>
</body>
</html>
|
