v.to.rast(1)

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

NAME

6       v.to.rast   -  Converts  a  binary  GRASS vector map layer into a GRASS
7       raster map layer.
8

KEYWORDS

10       vector
11

SYNOPSIS

13       v.to.rast
14       v.to.rast help
15       v.to.rast   input=name   output=name    [use=string]      [column=name]
16       [layer=integer]   [value=float]   [rows=integer]   [--overwrite]
17
18   Flags:
19       --overwrite
20
21   Parameters:
22       input=name
23           Name of input vector map
24
25       output=name
26           Name for output raster map
27
28       use=string
29           Source of raster values:
30                     attr  -  read values from attribute table      cat  - use
31           category  values        val   -  use  value  specified   by   value
32           option        z      -   use   z  coordinate  (points  or  contours
33           only)        dir  - output as flow direction (lines only)  Options:
34           attr,cat,val,z,dir Default: attr
35
36       column=name
37           Column name (type must be numeric)
38
39       layer=integer
40           Layer number Default: 1
41
42       value=float
43           Raster value Default: 1
44
45       rows=integer
46           number of rows to hold in memory Default: 4096
47

DESCRIPTION

49       v.to.rast  transforms  GRASS  vector  map  layers into GRASS raster map
50       layer format.
51

NOTES

53       v.to.rast will only affect data in areas lying inside the boundaries of
54       the  current  geographic  region.   Before  running v.to.rast, the user
55       should therefore ensure that the current geographic region is correctly
56       set and that the region resolution is at the desired level.
57
58       Either  the  column parameter or the value parameter must be specified.
59       The use option may be specified alone when using the dir option.
60
61       use options are:
62              attr - read values from attribute table (default)  cat   -  read
63              values  from category val  - use value specified by value option
64              z    - use z coordinate (points or contours only) dir  -  output
65              as flow direction in degrees (lines only)
66
67       The  column parameter uses an existing column from the vector map data‐
68       base table as the category value in the output raster map. Existing ta‐
69       ble columns can be shown by using db.describe.
70
71       An  empty  raster map layer will be created if the vector map layer has
72       not been assigned  category/attribute  labels  (e.g.,  through  use  of
73       v.category option=add).
74
75       Otherwise:
76              Labeled areas and/or centroids will produce filled raster cover‐
77              ages with edges that straddle the original area boundary as long
78              as the boundary is NOT labeled.
79              (Use  v.category  option=del  type=boundary to remove.)  Labeled
80              lines and boundaries will produce lines of  raster  cells  which
81              touch the original vector line. This tends to be more aggressive
82              than area-only conversions.  Points and orphaned centroids  will
83              be converted into single cells on the resultant raster map.
84
85       Flow directions are given in degrees counterclockwise from east.
86

EXAMPLES

88       1. Convert a vector map and use column SPEED from attribute table
89
90       db.describe -c table=vect_map
91       ncols:3
92       Column 1: CAT
93       Column 2: SPEED
94       Column 3: WIDTH
95
96       v.to.rast in=vect_map out=raster_map col=SPEED
97
98
99       2. Calculate stream directions from a river vector map (Spearfish)
100
101       v.to.rast in=streams out=streamsdir use=dir
102
103

AUTHORS

108       Original  code:  Michael  Shapiro,  U.S.  Army Construction Engineering
109       Research Laboratory
110       GRASS 6 updates: Radim Blazek, ITC-Irst, Trento, Italy
111       Stream directions: Jaro Hofierka and Helena Mitasova
112
113       Last changed: $Date: 2007/01/28 16:30:34 $
114
115       Full index
116
117
118
119GRASS 6.2.2                                                       v.to.rast(1)