NAME¶

v.to.rast - Converts (rasterize) a vector map into a raster map.

KEYWORDS¶

vector, raster, conversion

SYNOPSIS¶

v.to.rast v.to.rast help v.to.rast input=name [layer=integer] [type=string[,string,...]] output=name use= string [column=name] [rgbcolumn=name] [ labelcolumn=name] [value= float] [rows=integer] [--overwrite] [-- verbose] [--quiet]

Flags:¶

--overwrite

 

Allow output files to overwrite existing files

--verbose

 

Verbose module output

--quiet

 

Quiet module output

Parameters:¶

input=name

 

Name of input vector map

layer=integer

 

Layer number

 

A single vector map can be connected to multiple database tables. This number determines which table to use.

 

Default: 1

type=string[,string,...]

 

Feature type

 

Options: point,line,area

 

Default: point,line,area

output=name

 

Name for output raster map

use=string

 

Source of raster values

 

Options: attr,cat,val,z,dir

 

Default: attr

 

attr: read values from attribute table

 

cat: use category values

 

val: use value specified by value option

 

z: use z coordinate (points or contours only)

 

dir: output as flow direction (lines only)

column=name

 

Name of column for 'attr' parameter (data type must be numeric)

rgbcolumn=name

 

Name of color definition column (with RRR:GGG:BBB entries)

labelcolumn=name

 

Name of column used as raster category labels

value=float

 

Raster value (for use=val)

 

Default: 1

rows=integer

 

Number of rows to hold in memory

 

Default: 4096

DESCRIPTION¶

v.to.rast transforms GRASS vector map layers into GRASS raster map layer format. Optionally, attributes can be converted into raster category labels.

NOTES¶

v.to.rast will only affect data in areas lying inside the boundaries of the current geographic region. Before running v.to.rast, the user should therefore ensure that the current geographic region is correctly set and that the region resolution is at the desired level. Either the column parameter or the value parameter must be specified. The use option may be specified alone when using the dir option. use options are: The column parameter uses an existing column from the vector map database table as the category value in the output raster map. Existing table columns can be shown by using db.describe. An empty raster map layer will be created if the vector map layer has not been assigned category/attribute labels (e.g., through use of v.category option=add). Otherwise: Flow directions are given in degrees counterclockwise from east. Raster category labels are supported for all of use= except use=z.

EXAMPLES¶

1. Convert a vector map and use column SPEED from attribute table db.describe -c table=vect_map ncols:3 Column 1: CAT Column 2: SPEED Column 3: WIDTH v.to.rast in=vect_map out=raster_map col=SPEED 2. Calculate stream directions from a river vector map (Spearfish) v.to.rast in=streams out=streamsdir use=dir 3. Convert a vector polygon map to raster including descriptive labels (Spearfish) v.to.rast in=fields out=myfields use=attr col=cat labelcol=label r.category myfields

SEE ALSO¶

db.describe, v.category

AUTHORS¶

Original code: Michael Shapiro, U.S. Army Construction Engineering Research Laboratory GRASS 6.0 updates: Radim Blazek, ITC-irst, Trento, Italy Stream directions: Jaro Hofierka and Helena Mitasova GRASS 6.3 code cleanup and label support: Brad Douglas Last changed: $Date: 2011-11-08 12:29:50 +0100 (Tue, 08 Nov 2011) $ Full index © 2003-2014 GRASS Development Team