v.kernel(1)

1v.kernel(1)                   Grass User's Manual                  v.kernel(1)
2
3
4

NAME

6       v.kernel   -  Generates  a  raster  density map from vector points data
7       using a moving 2D isotropic Gaussian kernel or optionally  generates  a
8       vector density map on vector network with a 1D kernel
9

KEYWORDS

11       vector, kernel density
12

SYNOPSIS

14       v.kernel
15       v.kernel help
16       v.kernel   [-oqv]   input=name    [net=name]   output=string  stddevia‐
17       tion=float     [dsize=float]       [segmax=float]       [distmax=float]
18       [mult=float]
19
20   Flags:
21       -o  Try  to calculate an optimal standard deviation with 'stddeviation'
22           taken as maximum (experimental)
23
24       -q  Only calculate optimal standard deviation and exit (no map is writ‐
25           ten)
26
27       -v  Run verbosely
28
29   Parameters:
30       input=name
31           Input vector with training points
32
33       net=name
34           Input network vector map
35
36       output=string
37           output raster/vector map
38
39       stddeviation=float
40           stddeviation in map units
41
42       dsize=float
43           discretization error in map units Default: 0.
44
45       segmax=float
46           maximum length of segment on network Default: 100.
47
48       distmax=float
49           maximum distance from point to network Default: 100.
50
51       mult=float
52           multiply the density result by this number Default: 1.
53

DESCRIPTION

55       Generates  a  raster density map from vector points data using a moving
56       2D isotropic Gaussian kernel or optionally generates a  vector  density
57       map on vector network with a 1D kernel.
58

NOTES

60       The mult option is needed to overcome the limitation that the resulting
61       density in case of a vector map output is stored as category (Integer).
62       The density result stored as category may be multiplied by this number.
63
64       With the -o flag (experimental) the command tries to calculate an opti‐
65       mal standard deviation. The value of stddeviation is taken  as  maximum
66       value.  Standard  deviation  is  calculated  using ALL points, not just
67       those in the current region.
68

LIMITATIONS

70       The modules only considers the presence of point,  but  not  (yet)  any
71       attribute values.
72

AUTHOR

77       Stefano Menegon, ITC-irst, Trento, Italy
78       Radim Blazek (network part)
79
80       Last changed: $Date: 2005/01/11 10:23:39 $
81
82       Full index
83
84
85
86GRASS 6.2.2                                                        v.kernel(1)