NAME

       t.rast.to.vect  - Converts a space time raster dataset into a space time vector dataset

KEYWORDS

       temporal, conversion, raster, vector, time

SYNOPSIS

       t.rast.to.vect
       t.rast.to.vect --help
       t.rast.to.vect    [-ntszbv]   input=name   output=name    [where=sql_query]    type=string
       basename=string   [suffix=string]    [column=string]    [nprocs=integer]     [--overwrite]
       [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -n
           Register empty vector maps

       -t
           Do not create attribute tables

       -s
           Smooth corners of area features

       -z
           Write raster values as z coordinate
           Table is not created. Currently supported only for points.

       -b
           Do not build vector topology
           Name must be SQL compliant

       -v
           Use raster values as categories instead of unique sequence (CELL only)

       --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’

       type=string [required]
           Output feature type
           Options: point, line, area

       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

       column=string
           Name of attribute column to store value
           Default: value

       nprocs=integer
           Number of r.to.vect processes to run in parallel, more than 1 process  works  only  in
           conjunction with flag -t
           Default: 1

DESCRIPTION

       t.rast.to.vect is designed to convert a space time raster dataset into a space time vector
       dataset. This module works  as  a  front-end  to  r.to.vect  and  therefore  supports  all
       parameter  of this module. Hence, all raster map layers in a space time raster dataset are
       passed to r.to.vect that converts them into vector map layers (using point,line or area as
       conversion  criteria).   Please  refer  to  the  r.to.vect  documentation  for  a detailed
       description of the raster to vector conversion options.   The  new  generated  vector  map
       layers  will  be  registered  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.to.vect module instances. 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 layers should be converted  into  vector  map
       layers.

SEE ALSO

        r.to.vect, t.rast.db.select, t.info

AUTHOR

       Sören Gebbert, Geoinformatikbüro Dassau

       Last changed: $Date: 2015-09-05 18:13:18 +0200 (Sat, 05 Sep 2015) $

SOURCE CODE

       Available at: t.rast.to.vect source code (history)

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       © 2003-2018 GRASS Development Team, GRASS GIS 7.4.0 Reference Manual