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v.out.ascii(1grass) Grass User's Manual v.out.ascii(1grass)

NAME

v.out.ascii - Converts a GRASS binary vector map to a GRASS ASCII vector map.

KEYWORDS

vector, export

SYNOPSIS

v.out.ascii
 
v.out.ascii help
 
v.out.ascii [-or] input=name [output=name] [ format=string] [fs=character] [ dp=integer] [layer=integer] [ columns=name[,name,...]] [ where=sql_query] [--verbose] [--quiet]

Flags:

-o
 
Create old (version 4) ASCII file
-r
 
Only export points falling within current 3D region (points mode)
--verbose
 
Verbose module output
--quiet
 
Quiet module output

Parameters:

input=name
 
Name of input vector map
output=name
 
Path to resulting ASCII file or ASCII vector name if '-o' is defined
format=string
 
Output format
 
Options: point,standard
 
Default: point
fs=character
 
Field separator (points mode)
 
Default: |
dp=integer
 
Number of significant digits (floating point only)
 
Options: 0-32
 
Default: 8
layer=integer
 
Layer number
 
A single vector map can be connected to multiple database tables. This number determines which table to use.
 
Default: 1
columns=name[,name,...]
 
Name of attribute column(s) to be exported (point mode)
where=sql_query
 
WHERE conditions of SQL statement without 'where' keyword
 
Example: income = 10000

DESCRIPTION

v.out.ascii converts a GRASS vector map in binary format to a GRASS vector map in ASCII format. Using flag -o v.out.ascii output will be in old (version 4) ASCII format.
If the output parameter is not given then the coordinates of any point data within the vector map is sent to stdout.

NOTES

The v.in.ascii module performs the function of v.out.ascii in reverse; i.e. it converts vector maps in ASCII format to their binary format. These two companion module are useful both for importing and exporting vector maps between GRASS and other software, and for transferring data between machines.
If the format parameter is set to standard, a GRASS ASCII vector map will be exported, which may contain a mix of primitives including points, lines, boundaries, centroids, areas, faces, and kernels. The beginning of the output ascii file will contain a header listing any metadata for the input vector map, if such metadata exists. An example of the standard format is given below.
The header is similar as the head file of vector binary format but contains bounding box also. Key words are:
 
ORGANIZATION
 
DIGIT DATE
 
DIGIT NAME
 
MAP NAME
 
MAP DATE
 
MAP SCALE
 
OTHER INFO
 
ZONE
 
WEST EDGE
 
EAST EDGE
 
SOUTH EDGE
 
NORTH EDGE
 
MAP THRESH
 
The body begins with the row:
 
VERTI:
 
followed by records of primitives:
 
TYPE NUMBER_OF_COORDINATES [NUMBER_OF_CATEGORIES]
 

X Y [Z]
 
 

X Y [Z]
 
[ LAYER CATEGORY]
 
 
[ LAYER CATEGORY]
 
Everything above in [ ] is optional.
The primitive codes are as follows:
’P': point
’L': line
’B': boundary
’C': centroid
’F': face (3D boundary)
’K': kernel (3D centroid)
’A': area (boundary) - better use 'B'; kept only for backward compatibility
The coordinates are listed following the initial line containing the primitive code, the total number of vectors in the series, and (optionally) the number of categories (1 for a single layer, higher for multiple layers). Below that 1 or several lines follow to indicate the layer number and the category number (ID).
 
The order of coordinates is
 

X Y [Z]
 
In pre-GRASS 6 versions of the ASCII file, the order of coordinates is:
 
Y X
 
If old version is requested, the output files from v.out.ascii is placed in the $LOCATION/$MAPSET/dig_ascii/ and $LOCATION/$MAPSET/dig_att directory.
Only features with a category number will be exported. Use v.category to add them if needed.
v.out.ascii does not copy the dig_cats file associated with the binary vector input map to the new output file name. The user must copy the dig_cats file to the new output name if this is desired (e.g. using the UNIX cp command).
It is possible to output the coordinates of vertices in a non-points vector feature by first converting the vector feature to a points map with v.to.points and then exporting with v.out.ascii in points mode.

EXAMPLES

Standard mode

 
v.out.ascii input=quads format=standard
 
 
ORGANIZATION: US Army Const. Eng. Rsch. Lab
 
DIGIT DATE: May 1987
 
DIGIT NAME: grass
 
MAP NAME: Quads
 
MAP DATE: May 1987
 
MAP SCALE: 24000
 
OTHER INFO:
 
ZONE: 13
 
MAP THRESH: 18.288000
 
VERTI:
 
B 4
 

599587.1820962 4914067.53414294
 

589639.15126831 4913922.5687301
 

589440.96838162 4927803.62500018
 

599375.87959179 4927959.83330436
 
B 2
 

599375.87959179 4927959.83330436
 

599587.1820962 4914067.53414294
 
B 4
 

599587.1820962 4914067.53414294
 

609541.5508239 4914236.0597482
 

609316.10665227 4928116.8490555
 

599375.87959179 4927959.83330436
 
C 1 1
 

594125.63 4921115.58
 

1 1
 
C 1 1
 

604433.84 4921087.1
 

1 2
 

Point mode

 
v.out.ascii input=quads format=point
 
 
594125.63|4921115.58|1
 
604433.84|4921087.1|2
 
 
v.out.ascii input=archsites format=point where="cat > 5 and cat <= 8" columns=str1
 
 
600375|4925235|6|Prairie Site
 
606635|4920773|7|Jensen Pass
 
595755|4925300|8|No Name
 

SEE ALSO

v.category, v.in.ascii, v.to.points
 
GRASS SQL interface

AUTHORS

Michael Higgins, U.S. Army Construction Engineering Research Laboratory
 
James Westervelt, U.S. Army Construction Engineering Research Laboratory
 
Radim Blazek, ITC-Irst, Trento, Italy
 
Attribute selection added by Martin Landa, CTU in Prague, Czech Republic (2008/12)
Last changed: $Date: 2011-11-08 10:42:51 +0100 (Tue, 08 Nov 2011) $
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GRASS 6.4.2