t.rast.contour(1grass) GRASS GIS User's Manual t.rast.contour(1grass)
NAME
t.rast.contour - Produces a space time vector dataset of specified
contours from a space time raster dataset.
KEYWORDS
temporal, contour, raster, vector, time
SYNOPSIS
t.rast.contour
t.rast.contour --help
t.rast.contour [-nt] input=name output=name [where=sql_query] base-
name=string [suffix=string] [step=float] [lev-
els=float[,float,...]] [minlevel=float] [maxlevel=float] [cut=in-
teger] [nprocs=integer] [--overwrite] [--help] [--verbose]
[--quiet] [--ui]
Flags:
-n
Register empty vector maps
-t
Do not create attribute tables
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog
Parameters:
input=name [required]
Name of the input space time raster dataset
output=name [required]
Name of the output space time vector dataset
where=sql_query
WHERE conditions of SQL statement without ’where’ keyword used in
the temporal GIS framework
Example: start_time > ’2001-01-01 12:30:00’
basename=string [required]
Basename of the new generated output maps
A numerical suffix separated by an underscore will be attached to
create a unique identifier
suffix=string
Suffix to add at basename: set ’gran’ for granularity, ’time’ for
the full time format, ’num’ for numerical suffix with a specific
number of digits (default %05)
Default: gran
step=float
Increment between contour levels
levels=float[,float,...]
List of contour levels
minlevel=float
Minimum contour level
maxlevel=float
Maximum contour level
cut=integer
Minimum number of points for a contour line (0 -> no limit)
Default: 0
nprocs=integer
Number of r.contour processes to run in parallel, more than 1
process works only in conjunction with flag -t
Default: 1
DESCRIPTION
t.rast.contour is designed to produce a space time vector dataset of
specified contours from a space time raster dataset. This module works
as a front-end to r.contour and therefore supports all parameter of
this module. Hence, all raster map layers in a space time raster
dataset are successively passed to r.contour that computes the contour
lines. Please refer to the r.contour documentation for a detailed de-
scription. The new generated vector contour map layers will be regis-
tered in the output space time vector dataset, using the same time
stamps as their raster map layer origins.
This module supports the parallel processing of r.contour module in-
stances. The number of parallel processes can be set with the nprocs
option. However, this will only work in conjunction with the -t flag,
that avoids the creation of attribute tables. The parallel creation of
attribute tables is not supported.
The where option allows selecting subsets of the input space time
raster dataset.
The flag -n can be used to force the registration of empty vector map
layers. Empty vector maps may occur in case that empty raster map lay-
ers should be converted into vector map layers, or in case the chosen
steps or contour levels are not present in the raster map layers.
SEE ALSO
r.contour, t.rast.db.select, t.info
AUTHOR
Sören Gebbert, Geoinformatikbüro Dassau
SOURCE CODE
Available at: t.rast.contour source code (history)
Accessed: unknown
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GRASS 7.8.7 t.rast.contour(1grass)
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