NAME
r.in.ascii - Convert an ASCII raster text file into a (binary) raster map layer.
(GRASS Raster Data Import Program)
SYNOPSIS
r.in.ascii
r.in.ascii help
r.in.ascii [-ifds] input=name
output=name
[TITLE="phrase"]
[mult=multiplier]
DESCRIPTION
r.in.ascii allows a user to create a (binary) GRASS raster map layer
from an ASCII raster input file with (optional) TITLE.
OPTIONS
Flags:
- -i
- integer values are imported
- -f
- floating point values are imported
- -d
- double floating point values are imported
- -s
- SURFER (Golden Software) ascii grid file will be imported
Parameters:
- input=name
- Name of an existing ASCII raster file to be imported.
- output=name
- Name to be assigned to resultant binary raster map layer.
- TITLE="phrase"
- Title to be assigned to resultant raster map layer.
- mult=multiplier
- Multiply all raster cell values by multiplier.
multiplier is a floating point value, and has a default value of 1.0.
The 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) as is not required.
"multiplier" is an optional parameter to multiply each cell value.
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
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 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.
r.in.ascii handles floating point cell values.
The header information in ESRI Raster ASCII files differs from GRASS.
To convert an Arc/Info (ArcView) ASCII grid file into GRASS, click
here.
Also, see r.in.arc to import
ESRI Raster ASCII files.
SEE ALSO
m.flip,
r.out.ascii,
r.in.arc,
r.out.arc,
r.in.bin,
GRASS ASCII formats
AUTHOR
Michael Shapiro, U.S. Army Construction Engineering
Research Laboratory
Surfer support by Roger Miller
Last changed: $Date$