## NAME

t.rast.to.rast3 - Converts a space time raster dataset into a 3D raster map.

## KEYWORDS

temporal, conversion, raster, raster3d, voxel, time

## SYNOPSIS

t.rast.to.rast3
t.rast.to.rast3 --help
t.rast.to.rast3 input=name output=name [--overwrite] [--help] [--verbose] [--quiet] [--ui]

### Flags:

--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 for output 3D raster map

## DESCRIPTION

t.rast.to.rast3 is designed to convert a space time raster dataset (STRDS) into a space time voxel cube. A space time voxel cube is a 3 dimensional raster map layer (3D raster map or voxel map layer) that as time as unit for the z-dimension.

A space time raster dataset that should be converted into a space time voxel cube must have a valid temporal topology. Hence, overlapping or inclusion of time stamps is not allowed. The granularity of the STRDS is used to set the resolution of the 3D raster map layer and to sample the registered time stamped raster map layers.

Gaps between raster map layer in the STRDS will be represented by NULL values in the voxel map layer.

## NOTES

The reference time for all space time voxel cubes is 1900-01-0100:00:00. This allows the alignment space time voxel cubes with different granularities.

Be aware that the granularity of a STRDS is used to sample time stamped map layers! If you have gaps between monthly intervals that have the size of a second, the monthly intervals will be sampled by a second based granularity as well. This may result in millions of space time voxel cube layers!

### Management of open file limits

The maximum number of raster maps that can be processed is given by the per-user limit of the operating system. For example, both the the hard and soft limit for users is typically 1024. The soft limit can be changed with e.g. ulimit -n 4096 (UNIX-based operating systems) but not higher than the hard limit. If the latter is too low, you can as superuser add an entry in

    /etc/security/limits.conf
    # <domain>      <type>  <item>         <value>
    your_username  hard    nofile          4096

This will raise the hard limit to 4096 files. Also have a look at the overall limit of the operating system

    cat /proc/sys/fs/file-max

which, on modern Linux systems, is several 100,000 files.

## EXAMPLE

To create a voxel map layer from a subset of the tempmean_monthly space time dataset, run:

    # create the subset for 2012 data
    t.rast.extract input=tempmean_monthly output=tempmean_monthly_later_2012 \
                   where="start_time >= '2012-01-01'"

    # set the right 3D region
    g.region -p3 res3=500

    # convert to 3D raster map
    t.rast.to.rast3 input=tempmean_monthly_later_2012@climate_2009_2012 output=tempmean_monthly_2012

    t.info type=raster_3d input=tempmean_monthly_2012
     +-------------------- 3D Raster Dataset -------------------------------------+
     |                                                                            |
     +-------------------- Basic information -------------------------------------+
     | Id: ........................ tempmean_monthly_2012@climate_2009_2012
     | Name: ...................... tempmean_monthly_2012
     | Mapset: .................... climate_2009_2012
     | Creator: ................... lucadelu
     | Temporal type: ............. absolute
     | Creation time: ............. 2014-11-28 11:10:51.679294
     +-------------------- Absolute time -----------------------------------------+
     | Start time:................. 2012-01-01 00:00:00
     | End time:................... 2013-01-01 00:00:00
     +-------------------- Spatial extent ----------------------------------------+
     | North:...................... 320000.0
     | South:...................... 10000.0
     | East:.. .................... 935000.0
     | West:....................... 120000.0
     | Top:........................ 1357.0
     | Bottom:..................... 1345.0
     +-------------------- Metadata information ----------------------------------+
     | Datatype:................... DCELL
     | Number of columns:.......... 620
     | Number of rows:............. 1630
     | Number of cells:............ 12127200
     | North-South resolution:..... 500.0
     | East-west resolution:....... 500.0
     | Minimum value:.............. -0.534994
     | Maximum value:.............. 28.794653
     | Number of depths:........... 12
     | Top-Bottom resolution:...... 1.0
     | Registered datasets ........
     +----------------------------------------------------------------------------+

    r3.info tempmean_monthly_2012
     +----------------------------------------------------------------------------+
     | Layer:    tempmean_monthly_2012          Date: Fri Nov 28 11:10:50 2014    |
     | Mapset:   climate_2009_2012              Login of Creator: lucadelu        |
     | Location: nc_spm_temporal_workshop                                         |
     | DataBase: /grassdata                                                       |
     | Title:    Space time voxel cube                                            |
     | Units:    none                                                             |
     | Vertical unit: months                                                      |
     | Timestamp: none                                                            |
     |----------------------------------------------------------------------------|
     |                                                                            |
     |   Type of Map:  3d cell              Number of Categories: 0               |
     |   Data Type:    DCELL                                                      |
     |   Rows:         620                                                        |
     |   Columns:      1630                                                       |
     |   Depths:       12                                                         |
     |   Total Cells:  12127200                                                   |
     |   Total size:           28414287 Bytes                                     |
     |   Number of tiles:      4230                                               |
     |   Mean tile size:       6717 Bytes                                         |
     |   Tile size in memory:  23520 Bytes                                        |
     |   Number of tiles in x, y and  z:   47, 45, 2                              |
     |   Dimension of a tile in x, y, z:   35, 14, 6                              |
     |                                                                            |
     |        Projection: Lambert Conformal Conic (zone 0)                        |
     |            N:     320000    S:      10000   Res:   500                     |
     |            E:     935000    W:     120000   Res:   500                     |
     |            T:       1357    B:       1345   Res:     1                     |
     |   Range of data:   min = -0.53499434 max = 28.79465315                     |
     |                                                                            |
     |   Data Source:                                                             |
     |                                                                            |
     |                                                                            |
     |                                                                            |
     |   Data Description:                                                        |
     |    This space time voxel cube was created with t.rast.to.rast3             |
     |                                                                            |
     |   Comments:                                                                |
     |    r.to.rast3 input="2012_01_tempmean@climate_2009_2012,2012_02_tempmea\   |
     |    n@climate_2009_2012,2012_03_tempmean@climate_2009_2012,2012_04_tempm\   |
     |    ean@climate_2009_2012,2012_05_tempmean@climate_2009_2012,2012_06_tem\   |
     |    pmean@climate_2009_2012,2012_07_tempmean@climate_2009_2012,2012_08_t\   |
     |    empmean@climate_2009_2012,2012_09_tempmean@climate_2009_2012,2012_10\   |
     |    _tempmean@climate_2009_2012,2012_11_tempmean@climate_2009_2012,2012_\   |
     |    12_tempmean@climate_2009_2012" output="tempmean_monthly_2012" tilesi\   |
     |    ze=32                                                                   |
     |                                                                            |
     +----------------------------------------------------------------------------+

## SEE ALSO

r3.mapcalc, r3.info

## AUTHOR

Sören Gebbert, Thünen Institute of Climate-Smart Agriculture

## SOURCE CODE

Available at: t.rast.to.rast3 source code (history)

Latest change: Thursday Jan 26 14:10:26 2023 in commit: cdd84c130cea04b204479e2efdc75c742efc4843

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