1v.in.ascii(1) Grass User's Manual v.in.ascii(1)
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6 v.in.ascii - Creates a vector map from an ASCII points file or ASCII
7 vector file.
8
10 vector, import, ASCII, level1, area, line, point
11
13 v.in.ascii
14 v.in.ascii --help
15 v.in.ascii [-zentbri] input=name output=name [format=string] [sepa‐
16 rator=character] [text=character] [skip=integer] [columns=string]
17 [x=integer] [y=integer] [z=integer] [cat=integer] [--overwrite]
18 [--help] [--verbose] [--quiet] [--ui]
19 Flags:
21 -z
22 Create 3D vector map
23 -e
25 Create a new empty vector map and exit. Nothing is read from input.
26 -n
28 Do not expect a header when reading in standard format
29 -t
31 Do not create table in points mode
32 -b
34 Do not build topology
35 Do not build topology in points mode
36 -r
38 Only import points falling within current region (points mode)
39 -i
41 Ignore broken line(s) in points mode
42 --overwrite
44 Allow output files to overwrite existing files
45 --help
47 Print usage summary
48 --verbose
50 Verbose module output
51 --quiet
53 Quiet module output
54 --ui
56 Force launching GUI dialog
57 Parameters:
59 input=name [required]
60 Name of input file to be imported
61 ’-’ for standard input
62 output=name [required]
64 Name for output vector map
65 format=string
67 Input file format
68 Options: point, standard
69 Default: point
70 point: simple x,y[,z] list
71 standard: GRASS vector ASCII format
72 separator=character
74 Field separator
75 Special characters: pipe, comma, space, tab, newline
76 Default: pipe
77 text=character
79 Text delimiter
80 Special characters: doublequote, singlequote, none
81 skip=integer
83 Number of header lines to skip at top of input file (points mode)
84 Default: 0
85 columns=string
87 Column definition in SQL style (points mode)
88 For example: ’x double precision, y double precision, cat int, name
89 varchar(10)’
90 x=integer
92 Number of column used as x coordinate (points mode)
93 First column is 1
94 Default: 1
95 y=integer
97 Number of column used as y coordinate (points mode)
98 First column is 1
99 Default: 2
100 z=integer
102 Number of column used as z coordinate (points mode)
103 First column is 1. If 0, z coordinate is not used
104 Default: 0
105 cat=integer
107 Number of column used as category (points mode)
108 First column is 1. If 0, unique category is assigned to each row
109 and written to new column ’cat’
110 Default: 0
111
113 v.in.ascii converts a vector map in GRASS ASCII vector format to a vec‐
114 tor map in binary format. The module may import two formats:
115 · standard contains all data types, each coordinate on one row
117 · point (default) reads only points, each point defined on one
119 row. Values are separated by a user-definable delimiter. If the
120 columns option is not defined, default names are used. It is
121 possible to specify the column order for the x,y,z coordinates
122 and category values.
123 v.out.ascii performs the function of v.in.ascii in reverse; i.e., it
125 converts vector maps in binary format to GRASS ASCII vector format.
126 These two companion programs are useful both for importing and export‐
127 ing vector maps between GRASS and other software, and for transferring
128 data between machines.
129
131 The input is read from the file specified by the input option or from
132 standard input.
133 The field separator may be a character, the word ’tab’ (or ’\t’) for
135 tab, ’space’ (or ’Â ’) for a blank, or ’comma’ (or ’,’) for a comma.
136 An attribute table is only created if it is needed, i.e. when at least
138 one attribute column is present in the input file besides geometry col‐
139 umns. The attribute column will be auto-scanned for type, but may be
140 explicitly declared along with the geometry columns using the columns
141 parameter.
142 Use the -z flag to convert ASCII data into a 3D vector map.
144 In special cases of data import, such as the import of large LIDAR
146 datasets (millions of data points), it may be necessary to disable
147 topology support (vector level 1) due to memory constraints. This is
148 done with the -b flag. As only very few vector modules support points
149 data processing at vector level 1, usually topology is required (vector
150 level 2). Therefore it is recommended that the user first try to import
151 the data without creating a database (the -t flag) or within a subre‐
152 gion (the -r flag) before resorting to the disabling of topology.
153 If old version is requested, the output files from v.out.ascii is
155 placed in the $LOCATION/$MAPSET/dig_ascii/ and $LOCA‐
156 TION/$MAPSET/dig_att directory.
157 Import of files without category column
159 If the input file does not contain a category column, there is the pos‐
160 sibility to auto-generate these IDs (categories). To automatically add
161 an additional column named ’cat’, the cat parameter must be set to the
162 virtual column number 0 (cat=0). This is the default action if the cat
163 parameter is not set.
164 Importing from a spreadsheet
166 Data may be imported from many spreadsheet programs by saving the
167 spreadsheet as a comma separated variable (.csv) text file, and then
168 using the separator=’,’ or separator=comma option with v.in.ascii in
169 points mode. If the input file contains any header lines, such as col‐
170 umn headings, the skip parameter should be used. These skipped header
171 lines will be written to the map’s history file for later reference
172 (read with v.info -h). The skip option only works in points mode.
173 Any line starting with the hash character (’#’) will be treated as a
175 comment and skipped completely if located in the main data file. If
176 located in the header, as defined by the skip parameter, it will be
177 treated as a header line and written to the history file.
178 Import of sexagesimal degree (degree, minutes, seconds, DMS)
180 The import of DMS formatted degrees is supported (in this case no sign
181 but N/S, E/W characters are used to indicate the hemispheres). While
182 the positions are internally translated into decimal degrees during the
183 import, the original DMS values are maintained in the attribute table.
184 This requires both the latitude and the longitude columns to be defined
185 as varchar(), not as numbers. A warning will be issued which can be
186 ignored. See GRASS ASCII vector format specification for details.
187 Importing only selected columns
189 Although v.in.ascii doesn’t have an option to specify which columns
190 should be imported, you can use a shell filter to achieve the same
191 effect, e.g.:
192 # Print out the column number for each field, supposing the file has a header
193 head -1 input_file | tr ’<the_field_separator_character>’ ’\n’ | cat -n
194 # From the listing, select the columns you want and feed them to v.in.ascii
195 # use input=- to read from stdin
196 cut -d<the_field_separator_character> -f<comma-separated_list_of_columns> input_file | v.in.ascii in=- <your_options>
197
199 Example 1a) - standard format mode
200 Sample ASCII polygon vector map for ’standard’ format mode. The two
201 areas will be assigned categories 20 and 21. For details on the struc‐
202 ture of standard format data files see the second reference at the bot‐
203 tom of this page.
204 echo "ORGANIZATION: GRASS Development Team
206 DIGIT DATE: 1/9/2005
207 DIGIT NAME: -
208 MAP NAME: test
209 MAP DATE: 2005
210 MAP SCALE: 10000
211 OTHER INFO: Test polygons
212 ZONE: 0
213 MAP THRESH: 0.500000
214 VERTI:
215 B 6
216 5958812.48844435 3400828.84221011
217 5958957.29887089 3400877.11235229
218 5959021.65906046 3400930.7458436
219 5959048.47580612 3400973.65263665
220 5959069.92920264 3401032.64947709
221 5958812.48844435 3400828.84221011
222 C 1 1
223 5958952.42189184 3400918.23126419
224 1 20
225 B 4
226 5959010.9323622 3401338.36037757
227 5959096.7459483 3401370.54047235
228 5959091.38259917 3401450.99070932
229 5959010.9323622 3401338.36037757
230 C 1 1
231 5959063.08352122 3401386.98533277
232 1 21" | v.in.ascii in=- format=standard output=test_polygons
233 Example 1b) - standard format mode
235 Sample ASCII 3D line vector map for ’standard’ format mode with simpli‐
236 fied input (note the space field separator). Note the -z flag indicat‐
237 ing 3D vector input, and the -n flag indicating no vector header should
238 be expected from the input file.
239 echo "L 5 1
240 591336 4927369 1224
241 594317 4925341 1292
242 599356 4925162 1469
243 602396 4926653 1235
244 607524 4925431 1216
245 1 321 " | v.in.ascii -zn in=- out=line3d format=standard
246 This can be used to create a vector line of a GPS track: the GPS points
247 have to be stored into a file with a preceding ’L’ and the number of
248 points (per line).
249 Example 2 - point format mode
251 Generate a 2D points vector map ’coords.txt’ as ASCII file:
252 1664619|5103481
253 1664473|5095782
254 1664273|5101919
255 1663427|5105234
256 1663709|5102614
257 Import into GRASS:
259 v.in.ascii input=coords.txt output=mymap
260 As the cat option is set to 0 by default, an extra column ’cat’ con‐
261 taining the category numbers will be auto-generated.
262 Example 3 - point format mode
264 Generate a 2D points vector map ’points.dat’ as ASCII file:
265 1|1664619|5103481|studna
266 2|1664473|5095782|kadibudka
267 3|1664273|5101919|hruska
268 4|1663427|5105234|mysi dira
269 5|1663709|5102614|mineralni pramen
270 Import into GRASS:
272 cat points.dat | v.in.ascii in=- out=mypoints x=2 y=3 cat=1 \
273 columns=’cat int, x double precision, y double precision, label varchar(20)’
274 The module is reading from standard input, using the default ’|’ (pipe)
276 delimiter.
277 Example 4 - point format mode - CSV table
279 Import of a 3D points CSV table (’points3d.csv’) with attributes:
280 "num","X","Y","Z","T"
281 1,2487491.643,5112118.33,120.5,18.62
282 2,2481985.459,5109162.78,123.9,18.46
283 3,2478284.289,5105331.04,98.3,19.61
284 Import into GRASS:
286 # import: skipping the header line, categories generated automatically,
287 # column names defined with type:
288 v.in.ascii -z in=points3d.csv out=mypoints3D separator=comma \
289 columns="num integer, x double precision, y double precision, z double precision, temp double precision" \
290 x=2 y=3 z=4 skip=1
291 # verify column types
292 v.info -c mypoints3D
293 # verify table content
294 v.db.select mypoints3D
295 Example 5 - point format mode
297 Generating a 3D points vector map from DBMS (idcol must be an integer
298 column):
299 echo "select east,north,elev,idcol from mytable" | db.select -c | v.in.ascii in=- -z out=mymap
300 With in=-, the module is reading from standard input, using the default
301 ’|’ (pipe) delimiter.
302 The import works for 2D maps as well (no elev column and no ’-z’ flag).
303 Example 6 - point format mode
305 Generate a 3D points vector map ’points3d.dat’ with attributes as ASCII
306 file:
307 593493.1|4914730.2|123.1|studna|well
308 591950.2|4923000.5|222.3|kadibudka|outhouse
309 589860.5|4922000.0|232.3|hruska|pear
310 590400.5|4922820.8|143.2|mysi dira|mouse hole
311 593549.3|4925500.7|442.6|mineralni pramen|mineral spring
312 600375.7|4925235.6|342.2|kozi stezka|goat path
313 Import into GRASS:
315 #As the ’cat’ option is set to 0 by default, an extra column ’cat’
316 #containing the IDs will be auto-generated (no need to define that):
317 cat points3d.dat | v.in.ascii in=- -z z=3 cat=0 out=mypoints3D \
318 columns=’x double precision, y double precision, z double precision, \
319 label_cz varchar(20), label_en varchar(20)’
320 v.info -c mypoints3D
321 v.info mypoints3D
322 Example 7 - point format mode
324 Generate points file by clicking onto the map:
325 #For LatLong locations:
326 d.where -d -l | awk ’{printf "%f|%f|point\n", $1, $2}’ | v.in.ascii in=- out=points \
327 columns=’x double precision, y double precision, label varchar(20)’
328 #For other projections:
329 d.where | awk ’{printf "%f|%f|point\n", $1, $2}’ | v.in.ascii in=- out=points \
330 columns=’x double precision, y double precision, label varchar(20)’
331 The ’point’ string (or some similar entry) is required to generate a
332 database table. When simply piping the coordinates (and optionally
333 height) without additional column(s) into v.in.ascii, only the vector
334 map geometry will be generated.
335 Example 8 - point format mode
337 Convert ground control points into vector points:
338 cat $MAPSET/group/$GROUP/POINTS | v.in.ascii in=- out=$GROUP_gcp separator=space skip=3 \
339 col=’x double precision, y double precision, x_target double precision, \
340 y_target double precision, ok int’
341
343 SQL command notes for creating databases
344 GRASS ASCII vector format specification
345
347 db.execute, r.in.ascii, r.in.poly, r.in.xyz, v.build, v.build.poly‐
348 lines, v.centroids, v.clean, v.db.connect, v.import, v.info,
349 v.in.lines, v.in.mapgen, v.out.ascii
350
352 Michael Higgins, U.S.Army Construction Engineering Research Laboratory
353 James Westervelt, U.S.Army Construction Engineering Research Laboratory
354 Radim Blazek, ITC-Irst, Trento, Italy
355
357 Available at: v.in.ascii source code (history)
358 Main index | Vector index | Topics index | Keywords index | Graphical
360 index | Full index
361 © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual
363GRASS 7.8.2 v.in.ascii(1)