Ubuntu Manpage: r3.to.rast - Converts 3D raster maps to 2D raster maps

name
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description
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author
source code

NAME

       r3.to.rast  - Converts 3D raster maps to 2D raster maps

KEYWORDS

       raster3d, conversion, raster, voxel

SYNOPSIS

       r3.to.rast
       r3.to.rast --help
       r3.to.rast    [-mr]    input=string   output=string    [type=string]     [multiply=float]     [add=float]
       [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -m
           Use 3D raster mask (if exists) with input map

       -r
           Use the same resolution as the input 3D raster map for the 2D output maps, independent of the current
           region settings

       --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=string [required]
           3D raster map(s) to be converted to 2D raster slices

       output=string [required]
           Basename for resultant raster slice maps

       type=string
           Type of raster map to be created
           Storage type for resultant raster map
           Options: CELL, FCELL, DCELL
           CELL: Integer
           FCELL: Single precision floating point
           DCELL: Double precision floating point

       multiply=float
           Value to multiply the raster values with
           Coefficient a in the equation y = ax + b

       add=float
           Value to add to the raster values
           Coefficient b in the equation y = ax + b

DESCRIPTION

Converts one 3D raster map into several 2D raster maps (depends on depths). If the 2D and 3D region
settings are different, the 3D resolution will be adjusted to the 2D resolution (the depths are not
touched). The user can force r3.to.rast to use the 2D resolution of the input 3D raster map for the
output maps, independently from the current region settings.

How r3.to.rast works

Map type conversions
Type of resulting 2D raster maps is determined by the type of the input 3D raster, i.e. 3D raster of type
DCELL (double) will result in DCELL 2D rasters. A specific type for 2D rasters can be requested using the
type option.

The type option is especially advantageous when the 3D raster map stores categories (which need to be
stored as floating point numbers) and the 2D raster map should be also categorical, i.e. use integers.
The type is set to CELL in this case.

Modifying the values
The values in the 3D raster map can be modified prior to storing in the 2D raster map. The values can be
scaled using the option multiply and a constant value can be added using the option add. The new value
is computed using the following equation:
y = ax + b
where x is the original value, a is the value of multiply option, b is the value of add option, and y is
the new value. When multiply is not provided, the value of a is 1. When add is not provided, the value of
b is 0.

NOTES

       Every slice  of  the  3D  raster  map  is  copied  to  one  2D  raster  map.  The  maps  are  named  like
       output_slicenumber. Slices are counted from bottom to the top, so the bottom slice has number 1.

       The number of slices is equal to the number of depths.

       To round floating point values to integers when using type=CELL, the add option should be set to 0.5.

AUTHOR

       Sören Gebbert Vaclav Petras, NCSU GeoForAll Lab

       Last changed: $Date: 2016-12-26 23:22:38 +0100 (Mon, 26 Dec 2016) $

SOURCE CODE

       Available at: r3.to.rast source code (history)

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