## NAME

r3.in.ascii

## DESCRIPTION

r3.in.ascii allows a user to create a (binary) GRASS 3D raster map layer from a 3D ASCII raster input file with (optional) TITLE.

Note that for compression the none option only specifies that neither LZW nor RLE is used for compression. It does not turn off the compression all together. 3D raster maps do not support non-compressed files.

The tiledimension parameter defines the dimension of the tiles used in the output file. The format is: XxYxZ

The nv parameter specifies which value to convert to NULL-value. If the specified value is none, no conversion is performed. Default is none.

## NOTES

The format of the 3D ASCII file:

    north: floating point
    south: floating point
    east: floating point
    west: floating point
    top: floating point
    bottom: floating point
    rows: integer
    cols: integer
    levels: integer

This header is followed by the cell values in floating point format organized in rows with constant col and level coordinate. The rows are organized by constant level coordinate. Individual cell values are separated by space or CR.

NOTE: Currently, after the file has been imported, the stored values are compared with the original data. This feature is used to find bugs in the library at an early stage and will be turned off as soon as confidence has built up.

## EXAMPLES

4x3x2 sample. Note, that lower-left (SW) corner of the bottom level comes first. This array format, where EW is preserved but NS is flipped, is sometimes known as "ij" coordinates. This is opposite to r.in.ascii's format, which places the SW corner at the beginning of the last row of data.

    north: 3.0
    south: 0.0
    east: 4.0
    west: 0.0
    top: 2.0
    bottom: 0.0
    rows: 3
    cols: 4
    levels: 2
    x1,y1,z1  x2,y1,z1  x3,y1,z1  x4,y1,z1
    x1,y2,z1  x2,y2,z1  x3,y2,z1  x4,y2,z1
    x1,y3,z1  x2,y3,z1  x3,y3,z1  x4,y3,z1
    x1,y1,z2  x2,y1,z2  x3,y1,z2  x4,y1,z2
    x1,y2,z2  x2,y2,z2  x3,y2,z2  x4,y2,z2
    x1,y3,z2  x2,y3,z2  x3,y3,z2  x4,y3,z2

Sample ASCII voxel map with one layer and several rows and columns (Spearfish area):

    north: 4925010.000000
    south: 4924890.000000
    east: 596760.000000
    west: 596610.000000
    top: 1.000000
    bottom: 0.000000
    rows: 4
    cols: 5
    levels: 1
    1204.74 1204.48 1204.19 1203.81 1203.39
    1203.89 1203.67 1203.34 1202.98 1202.43
    1203.05 1202.80 1202.51 1202.11 1201.48
    1202.10 1201.92 1201.62 1201.27 1200.68

## AUTHORS

Roman Waupotitsch, Michael Shapiro, Helena Mitasova, Bill Brown, Lubos Mitas, Jaro Hofierka

## SEE ALSO

r.in.ascii, r3.out.ascii, v.to.rast3

Last changed: $Date: 2011-09-13 22:13:36 +0200 (Tue, 13 Sep 2011) $

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