v.out.ascii performs the function of v.in.ascii in reverse; i.e., it converts vector maps in binary format to GRASS ASCII vector format. These two companion programs are useful both for importing and exporting vector maps between GRASS and other software, and for transferring data between machines.
The field separator may be a character, the word 'tab' (or '\t') for tab, 'space' (or ' ') for a blank, or 'comma' (or ',') for a comma.
An attribute table is only created if it is needed, i.e. when at least one attribute column is present in the input file besides geometry columns. The attribute column will be auto-scanned for type, but may be explicitly declared along with the geometry columns using the columns parameter.
Use the -z flag to convert ASCII data into a 3D vector map.
In special cases of data import, such as the import of large LIDAR datasets (millions of data points), it may be necessary to disable topology support (vector level 1) due to memory constraints. This is done with the -b flag. As only very few vector modules support points data processing at vector level 1, usually topology is required (vector level 2). Therefore it is recommended that the user first try to import the data without creating a database (the -t flag) or within a subregion (the -r flag) before resorting to the disabling of topology.
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.
Any line starting with the hash character ('#') will be treated as a comment and skipped completely if located in the main data file. If located in the header, as defined by the skip parameter, it will be treated as a header line and written to the history file.
# Print out the column number for each field, supposing the file has a header head -1 input_file | tr '<the_field_separator_character>' '\n' | cat -n # From the listing, select the columns you want and feed them to v.in.ascii # use input=- to read from stdin cut -d<the_field_separator_character> -f<comma-separated_list_of_columns> input_file | v.in.ascii in=- <your_options>
echo "ORGANIZATION: GRASS Development Team DIGIT DATE: 1/9/2005 DIGIT NAME: - MAP NAME: test MAP DATE: 2005 MAP SCALE: 10000 OTHER INFO: Test polygons ZONE: 0 MAP THRESH: 0.500000 VERTI: B 6 5958812.48844435 3400828.84221011 5958957.29887089 3400877.11235229 5959021.65906046 3400930.7458436 5959048.47580612 3400973.65263665 5959069.92920264 3401032.64947709 5958812.48844435 3400828.84221011 C 1 1 5958952.42189184 3400918.23126419 1 20 B 4 5959010.9323622 3401338.36037757 5959096.7459483 3401370.54047235 5959091.38259917 3401450.99070932 5959010.9323622 3401338.36037757 C 1 1 5959063.08352122 3401386.98533277 1 21" | v.in.ascii in=- format=standard output=test_polygons
echo "L 5 1 591336 4927369 1224 594317 4925341 1292 599356 4925162 1469 602396 4926653 1235 607524 4925431 1216 1 321 " | v.in.ascii -zn in=- out=line3d format=standard
1664619|5103481 1664473|5095782 1664273|5101919 1663427|5105234 1663709|5102614
Import into GRASS:
v.in.ascii input=coords.txt output=mymap
1|1664619|5103481|studna 2|1664473|5095782|kadibudka 3|1664273|5101919|hruska 4|1663427|5105234|mysi dira 5|1663709|5102614|mineralni pramen
Import into GRASS:
cat points.dat | v.in.ascii in=- out=mypoints x=2 y=3 cat=1 \ columns='cat int, x double precision, y double precision, label varchar(20)'
The module is reading from standard input, using the default '|' (pipe) delimiter.
"num","X","Y","Z","T" 1,2487491.643,5112118.33,120.5,18.62 2,2481985.459,5109162.78,123.9,18.46 3,2478284.289,5105331.04,98.3,19.61
Import into GRASS:
# import: skipping the header line, categories generated automatically, # column names defined with type: v.in.ascii -z in=points3d.csv out=mypoints3D separator=comma \ columns="num integer, x double precision, y double precision, z double precision, temp double precision" \ x=2 y=3 z=4 skip=1 # verify column types v.info -c mypoints3D # verify table content v.db.select mypoints3D
echo "select east,north,elev,idcol from mytable" | db.select -c | v.in.ascii in=- -z out=mymap
593493.1|4914730.2|123.1|studna|well 591950.2|4923000.5|222.3|kadibudka|outhouse 589860.5|4922000.0|232.3|hruska|pear 590400.5|4922820.8|143.2|mysi dira|mouse hole 593549.3|4925500.7|442.6|mineralni pramen|mineral spring 600375.7|4925235.6|342.2|kozi stezka|goat path
Import into GRASS:
#As the 'cat' option is set to 0 by default, an extra column 'cat' #containing the IDs will be auto-generated (no need to define that): cat points3d.dat | v.in.ascii in=- -z z=3 cat=0 out=mypoints3D \ columns='x double precision, y double precision, z double precision, \ label_cz varchar(20), label_en varchar(20)' v.info -c mypoints3D v.info mypoints3D
#For LatLong locations: d.where -d -l | awk '{printf "%f|%f|point\n", $1, $2}' | v.in.ascii in=- out=points \ columns='x double precision, y double precision, label varchar(20)' #For other projections: d.where | awk '{printf "%f|%f|point\n", $1, $2}' | v.in.ascii in=- out=points \ columns='x double precision, y double precision, label varchar(20)'
cat $MAPSET/group/$GROUP/POINTS | v.in.ascii in=- out=$GROUP_gcp separator=space skip=3 \ col='x double precision, y double precision, x_target double precision, \ y_target double precision, ok int'
Last changed: $Date$