v.edit(1grass) GRASS GIS User's Manual v.edit(1grass)
NAME
v.edit - Edits a vector map, allows adding, deleting and modifying se-
lected vector features.
KEYWORDS
vector, geometry, editing, line, node, point, vertex, level1
SYNOPSIS
v.edit
v.edit --help
v.edit [-rcnb1p] map=name [layer=string] [type=string[,string,...]]
tool=string [input=name] [move=x,y,z] [thresh-
old=float[,float,...]] [ids=range] [cats=range] [co-
ords=x,y[,x,y,...]] [bbox=x1,y1,x2,y2] [polygon=x,y[,x,y,...]]
[where=sql_query] [query=string] [bgmap=name[,name,...]]
[snap=string] [zbulk=value,step] [--overwrite] [--help] [--ver-
bose] [--quiet] [--ui]
Flags:
-r
Reverse selection
-c
Close added boundaries (using threshold distance)
-n
Do not expect header of input data
-b
Do not build topology
Advantageous when handling a large number of points
-1
Modify only first found feature in bounding box
-p
Connect parallel lines (using extend tools and threshold distance)
--overwrite
Allow output files to overwrite existing files
--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 to edit
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 ac-
cess this is the layer name.
Default: 1
type=string[,string,...]
Input feature type
Options: point, line, boundary, centroid
Default: point,line,boundary,centroid
tool=string [required]
Tool
Options: create, add, delete, copy, move, flip, catadd, catdel,
merge, break, snap, connect, extend, extendstart, extendend,
chtype, vertexadd, vertexdel, vertexmove, areadel, zbulk, select
create: Create new (empty) vector map
add: Add new features to existing vector map
delete: Delete selected features from vector map
copy: Copy selected features
move: Move selected features in vector map
flip: Flip direction of selected vector lines
catadd: Set new categories to selected vector features for defined
layer
catdel: Delete categories from selected vector features for defined
layer
merge: Merge selected vector lines
break: Break/split vector lines
snap: Snap vector features in given threshold
connect: Connect two lines
extend: Extend lines
extendstart: Extend start nodes
extendend: Extend end nodes
chtype: Change feature type (point<->centroid, line<->boundary)
vertexadd: Add new vertex to selected vector lines
vertexdel: Remove vertex from selected vector lines
vertexmove: Move vertex of selected vector lines
areadel: Delete selected areas from vector map (based on selected
centroids)
zbulk: Z bulk-labeling (automated assignment of z coordinate to
vector lines)
select: Select lines and print their ID’s
input=name
Name of file containing data in GRASS ASCII vector format
’-’ for standard input
move=x,y,z
Difference in x,y,z direction for moving feature or vertex
threshold=float[,float,...]
Threshold distance (coords,snap,query)
’-1’ for threshold based on the current resolution settings
Default: -1,0,0
ids=range
Feature ids
Example: 1,3,7-9,13
cats=range
Category values
Example: 1,3,7-9,13
coords=x,y[,x,y,...]
List of point coordinates
bbox=x1,y1,x2,y2
Bounding box for selecting features
polygon=x,y[,x,y,...]
Polygon for selecting features
where=sql_query
WHERE conditions of SQL statement without ’where’ keyword
Example: income < 1000 and population >= 10000
query=string
Query tool
For ’shorter’ use negative threshold value, positive value for
’longer’
Options: length, dangle
length: Select only lines or boundaries shorter/longer than thresh-
old distance
dangle: Select dangles shorter/longer than threshold distance
bgmap=name[,name,...]
Name of background vector map(s)
snap=string
Snap added or modified features in the given threshold to the near-
est existing feature
Options: no, node, vertex
Default: no
no: Not apply snapping
node: Snap only to node
vertex: Allow snapping also to vertex
zbulk=value,step
Starting value and step for z bulk-labeling
Pair: value,step (e.g. 1100,10)
DESCRIPTION
The module v.edit allows the user to edit a vector map via command line
interface.
v.edit supports only "simple" vector features: points, centroids, lines
and boundaries. Currently, only 2D vector features (except of
tool=zbulk) are supported.
Provides editing features’ geometry. Attribute data connected to the
vector map are not modified at all.
Vector features can be selected either by internal id, category number
cats, coordinates coords, bounding box bbox, polygon, where statement
(attribute data) or by query. Selecting features by coordinates is af-
fected by the current 2D resolution or by the threshold distance given
by threshold. The options are orthogonal, i.e. can be used in various
combinations. For example:
v.edit map=roads tool=select \
coord=599505,4921010,603389.0625,4918292.1875 \
threshold=10000 where="label=’interstate’"
selects all features (and prints their id’s to standard output) covered
by two bounding boxes (center at 599505,4921010 and
603389.0625,4918292.1875, size 2*10000) with attribute label=’inter-
state’.
NOTES
If no vector features are selected or the flag -b is used, topology is
not build at the end.
USAGE
Feature selection
Vector features can be selected in several ways:
• ids - using internal (unique) feature id’s
• cats - using category numbers
• coords - using x,y coordinate pairs (center of bounding box,
size defined by threshold)
• bbox - using bounding box
• polygon - using polygon (at least 3 coordinate pairs have to be
set)
• where - using where statement (attribute data)
• query - special query (e.g. minimal vector line length)
Additional parameters for vector feature specification are:
• layer - layer number (currently used only with cats or where
option)
• threshold - threshold distance used for selecting vector fea-
tures by coordinates
Tool description
• create - Create new (empty) vector map (see also v.in.ascii).
Optionally vector features (in GRASS ASCII vector format) can
be read from standard input (input=-) or from the text file
given by the input option.
• add - Add new vector features (defined in GRASS ASCII vector
format) to existing vector map. Features can be read from stan-
dard input or from the given text file (input option). If no
header is given, the -n flag must be used. Added features can
be snapped (defined by snap parameter) to nodes or vertices
based on threshold distance threshold.
• delete - Delete selected vector features from existing vector
map.
• copy - Make identical copy of selected vector features. If
background map bgmap is given copy features from background
map, not from currently modified vector map.
• move - Move selected features of existing vector map relatively
to their current location. This tool requires move option. The
option defines coordinates of the movement direction. Moved
features can be snapped (defined by snap parameter) to nodes or
vertices based on threshold distance threshold.
• flip - Flip direction of selected vector lines (lines or bound-
aries).
• catadd - Add new layer category(ies) to selected vector fea-
ture(s). Category can be later used for new database entry.
• catdel - Delete layer category(ies) of selected vector fea-
ture(s).
• merge - Merge (at least two) selected vector lines or bound-
aries. The geometry of the merged vector lines can be changed.
If the second line from two selected lines is in opposite di-
rection to the first, it will be flipped. See also module
v.build.polylines.
• break - Split given vector line or boundary into two lines on
location given by coords. If coords not given, breaks all se-
lected lines at each intersection (based on v.clean,
tool=break).
• snap - Snap vector features in given threshold. See also module
v.clean. Note that this tool supports only snapping to nodes.
Parameters snap and bgmap are ignored.
• connect - Connect selected lines or boundaries, the first given
line is connected to the second one. The second line is broken
if necessary. The lines are connected only if distance between
them is not greater than snapping threshold distance threshold.
• extend - Extend selected lines or boundaries without changing
the current shape. Similar to connect, but the first and second
lines are both extended until they intersect. The second line
is broken if necessary. The lines are extended only if distance
between them is not greater than snapping threshold distance
threshold. If the first and second lines are parallel and do
not intersect, no lines are extended. Use the -p flag to extend
the first line across the parallel gap.
• extendstart - Similar to extend, but extend at start nodes
only. Start nodes are used to select the second line and the
end node of that line can also be extended if it is within the
snapping threshold distance given by threshold.
• extendend - Similar to extend, but extend at end nodes only.
• chtype - Change feature type of selected geometry objects.
Points are converted to centroids, centroids to points, lines
to boundaries and boundaries to lines.
• vertexadd - Add vertex(ces) to the given vector lines or bound-
aries. Location of the new vertex is given by coord option. If
-1 is given only first found line or boundary in bounding box
is modified.
• vertexdel - Remove vertex(ces) specified by coords option. If
-1 is given only first found line or boundary in bounding box
is modified.
• vertexmove - Move vertex(ces) specified by coords option. Di-
rection of the movement is specified by the move option. If -1
is given only first found line or boundary in bounding box is
modified. Moved vertex can be snapped (defined snap) to nodes
or vertices based on threshold distance threshold.
• zbulk - Assign z coordinate to 3D vector lines in given bound-
ing box. The first found line will get z coordinate based on
value given by zbulk parameter. Z coordinate of other selected
lines will be increased by step given by zbulk parameter. This
tool strictly requires bbox and zbulk parameter. Also input
vector map must be 3D.
• select - Print comma separated list of selected line id’s. No
editing is done.
EXAMPLES
Create new vector map
Create new (empty) vector map:
v.edit tool=create map=vectmap
Create new vector map and read data from file ’roads.txt’:
v.out.ascii in=roads format=standard > roads.txt;
v.edit tool=create map=vectmap input=roads.txt
or alternatively
cat roads.txt | v.edit tool=create map=vectmap input=-
Add new features to existing vector map
Add a new point to the vector map (without header):
echo "P 1 1
640794 214874
1 1" | v.edit -n tool=add map=vectmap input=-
# insert new row for each category in attribute table if doesn’t exist yet
v.to.db map=vectmap option=cat
The input must be in GRASS ASCII vector format.
Add new features read from standard input:
v.out.ascii in=railroads format=standard | v.edit tool=add map=vectmap input=-
Delete selected features from vector map layer
Remove all vector features with category number 1 or 2:
v.edit tool=delete map=roads cats=1,2
Remove all vector features except of those with category number 1 or 2
(reverse selection):
v.edit -r tool=delete map=roads cats=1,2
Remove features with category 1 or 2 located on coordinates
600952.625,4926107 (bounding box based on the current 2D resolution):
g.region -d;
v.edit tool=delete map=roads cats=1,2 coords=600952.625,4926107
Remove all features with category 1 and 2 covered by two bounding boxes
(center coordinates 592542.892,4924766.996 and 603389.062,4918292.187,
size 1000 map units):
v.edit map=roads tool=delete \
coord=592542.892,4924766.996,603389.062,4918292.187 \
threshold=1000 cat=1,2
Copy selected features from background map
Copy all features with category number 1 from background map:
v.edit map=roads tool=copy bgmap=archsites cat=1
Move features
Move feature (vector point) located on coordinates 602580,4918480 to
coordinates 603580,4919480:
v.edit tool=move map=archsites coord=602580,4918480 th=1e-2 move=1000,1000
Move all features with category 1 1000 map units to the west and 1000
map units to the south. Moved features snap to nodes in threshold dis-
tance 10 map units:
v.edit tool=move map=roads cat=1 move=1000,-1000 snap=node threshold=-1,10
Move all features defined by bounding box 601530,4921560,602520,4922310
(W,S,E,N) 1000 map units to the east and 1000 map units to the north:
v.edit tool=move map=roads bbox=601530,4921560,602520,4922310 move=-1000,1000
Flip direction of vector lines
Flip direction of all vector lines:
v.edit tool=flip map=streams cats=1-9999 type=line
Add / delete layer category number
Add new layer/category 2/1, 2/3, 2/4, 2/5 to features covered by given
polygon:
v.edit tool=catadd map=roads \
polygon=599877.75,4925088.375,597164.812,4922524.5,601338.562,4920914.625 \
layer=2 cat=1,3-5
Delete layer/category 1/1, line id 1:
v.edit tool=catdel map=roads id=1 cats=5
Merge lines
Merge two lines with given category number:
v.edit map=roads tool=merge cat=4
Split line on given point
Split line id 810 on coordinates 604268,4923570 in threshold 50 map
units:
v.edit map=roads tool=break coords=604268,4923570 id=810 threshold=50
Break selected lines at each intersection
Break selected lines (with category number 1) at each intersection:
v.edit map=roads tool=break cat=1
Snap lines
Snap all lines using threshold distance 20 map units:
v.edit map=roads id=1-9999 tool=snap threshold=-1,20 type=line
Connect lines
Connect line id 48 to line id 565:
v.edit map=roads tool=connect id=48,565
Connect line id 48 to line id 565; line id 60 to line id 50. Maximum
threshold distance is 700 map units:
v.edit map=roads tool=connect id=48,565,60,50 threshold=-1,700
Add vertex
Add new vertex to the line located at 600952,4926107, threshold is set
to 1 map unit:
v.edit tool=vertexadd map=roads coords=600952,4926107 threshold=1
Delete vertices
Delete vertex located at 593191.608,4925684.849 (threshold set to 0.1
map units). Modify only lines with category 1:
v.edit tool=vertexdel map=roads coord=593191.608,4925684.849 \
threshold=1-e1 cats=1
Move vertices
Move vertices located at 604441,4921088 (threshold set to 100 map
units). Modify only lines with categories 1-10:
v.edit tool=vertexmove map=roads cats=1-10 coord=604441,4921088 \
threshold=100 move=1000,1000
Select features and print their id’s
Print id’s of selected features, e.g.:
v.edit map=soils@PERMANENT tool=select \
bbox=595733.8125,4919781.75,598536.1875,4917396.75 --q
Example with d.vect:
d.erase;
d.vect roads;
d.vect -i map=roads cats=`v.edit map=roads tool=select \
coord=592542.89243878,4924766.99622811,603389.0625,4918292.1875 \
threshold=1000 --q` col=red
Select all lines shorter (or equal) than 10 map units:
v.edit map=roads tool=select query=length threshold=-1,0,-10
Select from given bounding box all lines longer then 200 map units:
v.edit map=roads tool=select bbox=598260,4919730,605100,4926240 query=length threshold=-1,0,200
Fix height of contours
Input vector map contains 2D lines representing contours. Height can be
assign to the contours using tool=zbulk. First of all 2D lines need to
be converted to 3D lines:
v.extrude input=line2 output=line3 height=0 type=line
All lines which intersect with the line given by coordinates will be
modified. First found line will get height 1000 map units, height of
other selected lines will be increased by 10 map units.
v.edit a2 tool=zbulk bbox=586121.25049368,4911970.21547109,603092.60466035,4927071.25713776 \
zbulk=1000,10
SEE ALSO
v.in.ascii, v.info, v.build, v.build.polylines, v.clean, v.extrude,
v.split
See also wxGUI vector digitizer.
AUTHORS
Original author: Wolf Bergenheim - independent developer
Initial updates: Jachym Cepicky, Mendel University of Agriculture and
Forestry in Brno, Czech Republic
Major update by Martin Landa, FBK-irst (formerly ITC-irst), Trento,
Italy
Extend tools by Huidae Cho
SOURCE CODE
Available at: v.edit source code (history)
Accessed: unknown
Main index | Vector index | Topics index | Keywords index | Graphical
index | Full index
© 2003-2022 GRASS Development Team, GRASS GIS 7.8.7 Reference Manual
GRASS 7.8.7 v.edit(1grass)
Generated by dwww version 1.14 on Fri Jan 24 09:33:54 CET 2025.