v.info - GRASS GIS manual

NAME

v.info - Outputs basic information about a vector map.

KEYWORDS

vector, metadata, topology, extent, history, attribute columns, level1

SYNOPSIS

v.info

v.info --help

v.info [-hcget] map=name [layer=string] format=name [--help] [--verbose] [--quiet] [--ui]

Flags:

-h: Print history instead of info and exit
-c: Print types/names of table columns for specified layer instead of info and exit
-g: Print region info in shell script style
-e: Print extended metadata info in shell script style
-t: Print topology info in shell script style
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

map=name [required]: Name of vector map; Or data source for direct OGR access
layer=string: Layer number or name; Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.; Default: 1
format=name [required]: Output format; Options: plain, shell, json; Default: plain; plain: Human readable text output; shell: shell script style text output; json: JSON (JavaScript Object Notation)

DESCRIPTION
EXAMPLE
PYTHON
SEE ALSO
AUTHORS

DESCRIPTION

v.info reports some basic information (metadata) about a user-specified vector map and its topology status.

If topology info is not available (i.e., vector map cannot be opened on level 2), vector map extends and number of features need to be counted on the fly which may take some time.

Note that the flag -c only works when the vector map is connected to one or several attribute table(s). This connection can be shown or set with v.db.connect.

EXAMPLE

Basic metadata information

v.info map=geology

 +----------------------------------------------------------------------------+
 | Name:            geology                                                   |
 | Mapset:          PERMANENT                                                 |
 | Project:         nc_spm_08                                                 |
 | Database:        /home/martin/grassdata                                    |
 | Title:           North Carolina geology map (polygon map)                  |
 | Map scale:       1:1                                                       |
 | Map format:      native                                                    |
 | Name of creator: helena                                                    |
 | Organization:    NC OneMap                                                 |
 | Source date:     Mon Nov  6 15:48:53 2006                                  |
 |----------------------------------------------------------------------------|
 |   Type of map: vector (level: 2)                                           |
 |                                                                            |
 |   Number of points:       0               Number of centroids:  1832       |
 |   Number of lines:        0               Number of boundaries: 3649       |
 |   Number of areas:        1832            Number of islands:    907        |
 |                                                                            |
 |   Map is 3D:              No                                               |
 |   Number of dblinks:      1                                                |
 |                                                                            |
 |   Projection: Lambert Conformal Conic                                      |
 |                                                                            |
 |               N:   318117.43741634    S:    10875.82723209                 |
 |               E:   930172.31282271    W:   123971.19498978                 |
 |                                                                            |
 |   Digitization threshold: 0                                                |
 |   Comment:                                                                 |
 |                                                                            |
 +----------------------------------------------------------------------------+

Map history

v.info -h map=geology

COMMAND: v.in.ogr input="geol.shp" output="geology" min_area=0.0001 snap=-1
GISDBASE: /bigdata/grassdata05
LOCATION: ncfromfile MAPSET: PERMANENT USER: helena DATE: Mon Nov  6 15:48:53 2006
---------------------------------------------------------------------------------
1832 input polygons
total area: 1.276093e+11 (1832 areas)
overlapping area: 0.000000e+00 (0 areas)
area without category: 0.000000e+00 (0 areas)
---------------------------------------------------------------------------------

Note that while "project" is used by v.info elsewhere, history output uses the legacy term "location" because "LOCATION" is currently a part of the native vector format.

Attribute columns for given layer

v.info -c map=geology

Displaying column types/names for database connection of layer <1>:
INTEGER|cat
DOUBLE PRECISION|onemap_pro
DOUBLE PRECISION|PERIMETER
INTEGER|GEOL250_
INTEGER|GEOL250_ID
CHARACTER|GEO_NAME
DOUBLE PRECISION|SHAPE_area
DOUBLE PRECISION|SHAPE_len

Basic metadata information in shell script style

v.info -get map=geology

name=geology
mapset=PERMANENT
project=nc_spm_08
database=/home/martin/grassdata
title=North Carolina geology map (polygon map)
scale=1:1
format=native
creator=helena
organization=NC OneMap
source_date=Mon Nov  6 15:48:53 2006
level=2
map3d=0
num_dblinks=1
projection=Lambert Conformal Conic
digitization_threshold=0.000000
comment=
north=318117.43741634
south=10875.82723209
east=930172.31282271
west=123971.19498978
top=0.000000
bottom=0.000000
nodes=4556
points=0
lines=0
boundaries=3649
centroids=1832
areas=1832
islands=907
primitives=5481

v.info -g map=geology

north=318117.43741634
south=10875.82723209
east=930172.31282271
west=123971.19498978
top=0.000000
bottom=0.000000

Output in JSON format

{
    "name": "geology",
    "mapset": "PERMANENT",
    "project": "nc_spm_08_grass7",
    "database": "\/grassdata",
    "title": "North Carolina geology map (polygon map)",
    "scale": 1,
    "creator": "helena",
    "organization": "NC OneMap",
    "source_date": "Mon Nov  6 15:48:53 2006",
    "timestamp": null,
    "format": "native",
    "level": 2,
    "num_dblinks": 1,
    "attribute_layer_number": 1,
    "attribute_layer_name": "geology",
    "attribute_database": "\/grassdata\/nc_spm_08_grass7\/PERMANENT\/sqlite\/sqlite.db",
    "attribute_database_driver": "sqlite",
    "attribute_table": "geology",
    "attribute_primary_key": "cat",
    "projection": "Lambert Conformal Conic",
    "digitization_threshold": 0,
    "comment": "",
    "north": 318117.43741634465,
    "south": 10875.827232091688,
    "east": 930172.31282271142,
    "west": 123971.19498978264,
    "top": 0,
    "bottom": 0,
    "nodes": 2724,
    "points": 0,
    "lines": 0,
    "boundaries": 3649,
    "centroids": 1832,
    "areas": 1832,
    "islands": 907,
    "primitives": 5481,
    "map3d": false
}

PYTHON

See Python Scripting Library for more info.

Note: The Python tab in the wxGUI can be used for entering the following code:

import grass.script as gcore

gcore.vector_columns('geology')   # for `v.info -c`
gcore.vector_info_topo('geology') # for `v.info shell=topo`

Here is an example of how the JSON output format can be used to integrate Grass with other python libraries easily.

import grass.script as gs
import pandas as pd

# Run v.info command
busstops = gs.run_command("v.info", map="busstopsall", format="json")

# Load data into dataframe
df = pd.DataFrame([busstops])

# Display the DataFrame
print(df)

AUTHORS

Original author CERL
Updated to GRASS 6 by Radim Blazek, ITC-Irst, Trento, Italy
Level 1 support by Markus Metz
Updated to GRASS 7 by Martin Landa, CTU in Prague, Czech Republic

SOURCE CODE

Available at: v.info source code (history)

Latest change: Tuesday Nov 05 20:36:43 2024 in commit: 039183d9be2c1baf6e63fc07f6554fe6c2a06276