GRASS GIS manual: r.in.ascii

Note: A new GRASS GIS stable version has been released: GRASS GIS 7.8, available here.
Updated manual page: here

NAME

r.in.ascii - Converts a GRASS ASCII raster file to binary raster map.

KEYWORDS

raster, import, conversion, ASCII

SYNOPSIS

r.in.ascii

r.in.ascii --help

r.in.ascii [-s] input=name output=name [type=string] [title=phrase] [multiplier=float] [null_value=string] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-s: SURFER (Golden Software) ASCII file will be imported
--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 input file to be imported; '-' for standard input
output=name [required]: Name for output raster map
type=string: Type of raster map to be created; Default: CELL for integer values, DCELL for floating-point values; Options: CELL, FCELL, DCELL; CELL: Integer; FCELL: Single precision floating point; DCELL: Double precision floating point
title=phrase: Title for resultant raster map
multiplier=float: Multiplier for ASCII data; Default: read from header
null_value=string: String representing NULL value data cell; Default: read from header

DESCRIPTION
NOTES
EXAMPLE
SEE ALSO
AUTHOR

DESCRIPTION

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

The GRASS ASCII input file has a header section which describes the location and size of the data, followed by the data itself.

The header has 6 lines:

north:   xxxxxx.xx
south:   xxxxxx.xx
east:    xxxxxx.xx
west:    xxxxxx.xx
rows:    r 
cols:    c

The north, south, east, and west field values entered are the coordinates of the edges of the geographic region. The rows and cols field values entered describe the dimensions of the matrix of data to follow. The data which follows is r rows of c integers.

Optionally the following parameters can be defined in the header section:

null: nn
type: float
multiplier: 2.

"null" defines a string or number to be converted to NULL value (no data).
"type" defines the data type (int, float double) and is not required.
"multiplier" is an optional parameter to multiply each cell value.

NOTES

The geographic coordinates north, south, east, and west describe the outer edges of the geographic region. They run along the edges of the cells at the edge of the geographic region and not through the center of the cells at the edges. The NW value occurs at the beginning of the first line of data, and the SW value occurs at the beginning of the last line of data.

The data (which follows the header section) must contain r x c values, but it is not necessary that all the data for a row be on one line. A row may be split over many lines.

The imported cell type can be forced using the type option, default is auto-detection.

The header information in ESRI Raster ASCII files differs from GRASS. To convert an Arc/Info (ArcView) ASCII grid file into GRASS, see r.in.gdal.

SURFER (Golden Software) ASCII files may be imported by passing the -s flag.

EXAMPLE

The following is a sample input file to r.in.ascii:

north:                   4299000.00
south:                   4247000.00
east:                     528000.00
west:                     500000.00
rows:                         10   
cols:                         15   
null:                      -9999   

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

AUTHOR

Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
Surfer support by Roger Miller

Last changed: $Date$

SOURCE CODE

Available at: r.in.ascii source code (history)