GRASS GIS manual: r3.cross.rast

Note: This document is for an older version of GRASS GIS that is outdated. You should upgrade, and read the current manual page.

NAME

r3.cross.rast - Creates cross section 2D raster map from 3D raster map based on 2D elevation map.

KEYWORDS

raster3d, voxel

SYNOPSIS

r3.cross.rast
r3.cross.rast help
r3.cross.rast [-m] input=string elevation=string output=string [--overwrite] [--verbose] [--quiet]

Flags:

-m: Use 3D raster mask (if exists) with input map
--overwrite: Allow output files to overwrite existing files
--verbose: Verbose module output
--quiet: Quiet module output

Parameters:

input=string: Input 3D raster map for cross section.
elevation=string: 2D elevation map used to create the cross section map
output=string: Resulting cross section 2D raster map

DESCRIPTION

This module creates a cross section 2D map from one 3D raster volume map based on a 2D elevation map. It checks if the value of the elevation map is located in the z-coordinate space of the 3D map. If so, the 3D voxel value for this position is transferred to the related cross section output map cell, otherwise the NULL value is set.

How r3.cross.rast works

If the 2D and 3D region settings are different, the 2D resolution will be adjust to the 3D resolution.

NOTES

To create a cut plane elevation map use r.mapcalc. Some examples:

To create a cut plane elevation map in x direction type
r.mapcalc "cutplane = col()*x",
x be the value for the elevation. If the range of col() is 1 ... 10, the elevation map has the range 1 ... 10 if x == 1 and if x == 10 the range 10 ... 100
To create a cut plane elevation map in y direction type
r.mapcalc "cutplane = row()*x",
x be the value for the elevation. If the range of col() is 1 ... 10, the elevation map has the range 1 ... 10 if x == 1 and if x == 10 the range 10 ... 100
The user can also make a cut in y and x direction with r.mapcalc by using
r.mapcalc "cutplane = (row()+col())*x"

EXAMPLE

Simple Spearfish example

g.region -d
g.region res=150 res3=150 t=1000 b=0 tbres=100

# synthetic data, could be geological structures:
r3.mapcalc "map3d = sin(row())+sin(col())+sin(depth()*depth())"

#create a cutplane map
r.mapcalc "cutplane = col()*10"

#create the cross section map
r3.cross.rast input=map3d elevation=cutplane output=crosssection

AUTHOR

Sören Gebbert

Last changed: $Date: 2013-03-26 14:08:42 -0700 (Tue, 26 Mar 2013) $

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