NAME
r.in.ascii - Convert an ASCII raster text file into a (binary) raster map layer.
KEYWORDS
raster
SYNOPSIS
r.in.ascii
r.in.ascii help
r.in.ascii [-ifds] input=name output=name [title="phrase"] [mult=float] [nv=string] [--overwrite]
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
- --overwrite
- Force overwrite of output files
Parameters:
- input=name
- Ascii raster file to be imported
- output=name
- Name for output raster map
- title="phrase"
- Title for resultant raster map
- mult=float
- Multiplier for ascii data
- Default: 1.0 or read from header
- nv=string
- String representing NULL value data cell
- Default: * or read from header
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.
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 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.
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
r.out.ascii,
r.in.arc,
r.in.gdal,
r.out.arc,
r.in.bin,
r3.in.ascii,
GRASS ASCII formats
AUTHOR
Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
Surfer support by Roger Miller
Last changed: $Date: 2006/10/16 12:38:30 $
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