v.edit(1)

💖 v.edit(1) 💖

GRASS GIS User's Manual, bestie! This is the page for v.edit, and it's giving vector editing main character energy. No cap.

🌸 NAME 🌸

v.edit — edits a vector map, allows adding, deleting and modifying selected vector features.

✨ KEYWORDS ✨

vector, geometry, editing, line, node, point, vertex, level1

🎀 SYNOPSIS 🎀

okay so here's the synopsis, bestie:

v.edit
v.edit --help
v.edit [-rcnb1p] map=name  [layer=string]   [type=string[,string,...]]
tool=string  [input=name]   [move=x,y,z]   [threshold=float[,float,...]]
[ids=range]   [cats=range]   [coords=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]  [--verbose]  [--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 access 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 threshold 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 nearest 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. No GUI required, bestie — command line all the way. But careful: v.edit supports only "simple" vector features: points, centroids, lines and boundaries. Currently, only 2D vector features (except of tool=zbulk) are supported.

It provides editing features’ geometry. Attribute data connected to the vector map are not modified at all. So your attributes are safe, periodt.

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 affected 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=’interstate’.

💅 NOTES 💅

If no vector features are selected or the flag -b is used, topology is not build at the end.

✨ USAGE ✨

💖 Feature selection 💖

okay so bestie, before you can edit ANYTHING you gotta tell GRASS which features you're talking about. There's a whole menu of ways to do that:

• ids — you pick them by internal (unique) feature id's 🆔
• cats — you pick them by category numbers 🏷️
• coords — you pick them with x,y coordinate pairs (that's the center of the bounding box, and the size is defined by threshold) 📍
• bbox — you pick them with a bounding box 📦
• polygon — you pick them with a polygon (ngl you have to set at least 3 coordinate pairs for this one) 🔺
• where — you pick them with a where statement, aka the attribute data route 🗂️
• query — that's the special query vibe (think minimal vector line length, iykyk) 🔎

and then there's the extra supporting cast for specifying vector features:

• layer — layer number (rn it's only used with cats or the where option) 🧅
• threshold — the threshold distance used for selecting vector features by coordinates 📏

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🛠️ Tool description 🛠️

this is the moment, the main character list of everything v.edit can do to your map. periodt.

• create — Create a brand new (empty) vector map 💅 (see also v.in.ascii). If you want, vector features can also be read in (in GRASS ASCII vector format) from standard input (input=-) or from the text file you name with the input option.
• add — Add new vector features (defined in GRASS ASCII vector format) onto an existing vector map. Features can be read from standard input or from the text file given by the input option. If there's no header, you MUST use the -n flag. Added features can be snapped (defined by the snap parameter) to nodes or vertices based on threshold distance threshold.
• delete — Delete the selected vector features from an existing vector map 🗑️
• copy — Make an identical copy of the selected vector features. If a background map bgmap is given, it copies features from the background map, not from the vector map you're currently modifying.
• move — Move the selected features of an existing vector map relative to their current location. This tool requires the move option. That option defines the 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 the direction of selected vector lines (lines or boundaries) 🔄
• catadd — Add new layer category(ies) to the selected vector feature(s). That category can be used later for a new database entry.
• catdel — Delete layer category(ies) of the selected vector feature(s).
• merge — Merge (at least two) selected vector lines or boundaries. The geometry of the merged vector lines can be changed. If the second line out of the two selected lines is going in the opposite direction to the first, it will be flipped. See also module v.build.polylines.
• break — Split a given vector line or boundary into two lines at the location given by coords. If coords is not given, it breaks all selected lines at each intersection (based on v.clean, tool=break).
• snap — Snap vector features within a given threshold. See also module v.clean. Heads up: this tool supports only snapping to nodes. Parameters snap and bgmap are ignored. 🙈
• connect — Connect selected lines or boundaries; the first given line gets connected to the second one. The second line is broken if necessary. The lines are only connected if the distance between them is not greater than the snapping threshold distance threshold.
• extend — Extend selected lines or boundaries without changing the current shape. Similar to connect, but here the first AND second lines are both extended until they intersect. The second line is broken if necessary. The lines are only extended if the distance between them is not greater than the snapping threshold distance threshold. If the first and second lines are parallel and don't intersect, no lines are extended. Use the -p flag to extend the first line across the parallel gap.
• extendstart — Similar to extend, but it extends 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's within the snapping threshold distance given by threshold.
• extendend — Similar to extend, but it extends at end nodes only.
• chtype — Change the 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 boundaries. The location of the new vertex is given by the coord option. If -1 is given, only the first found line or boundary in the bounding box is modified.
• vertexdel — Remove vertex(ces) specified by the coords option. If -1 is given, only the first found line or boundary in the bounding box is modified.
• vertexmove — Move vertex(ces) specified by the coords option. The direction of the movement is specified by the move option. If -1 is given, only the first found line or boundary in the bounding box is modified. A moved vertex can be snapped (defined snap) to nodes or vertices based on threshold distance threshold.
• zbulk — Assign a z coordinate to 3D vector lines in a given bounding box. The first found line will get a z coordinate based on the value given by the zbulk parameter. The z coordinate of other selected lines will be increased by the step given by the zbulk parameter. This tool strictly requires the bbox and zbulk parameters. Also, the input vector map MUST be 3D. no cap. 🧊
• select — Print a comma separated list of selected line id's. No editing is done. Just vibes and a list. 📝

✨ EXAMPLES ✨

Okay bestie, this is the part where we actually do stuff 💅. Every command below is a real snack, and you can copy-paste them. No cap.

🌱 Create new vector map

Create a brand-new empty vector map:

v.edit tool=create map=vectmap

Want to create one and slurp data from roads.txt? Do this:

v.out.ascii in=roads format=standard > roads.txt;
v.edit tool=create map=vectmap input=roads.txt

Or alternatively, pipe it in like a boss:

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=-

Then insert a new row for each category in the attribute table if it doesn’t exist yet:

# 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. Periodt.

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 distance 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: Saturday Jan 17 05:41:21 2026

Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

© 2003-2025 GRASS Development Team, GRASS GIS 8.4.2 Reference Manual

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That’s the whole manual, bestie. This page is GRASS 8.4.2 and the footer says v.edit(1) — so you know it’s official. Accessed Saturday Jan 17 05:41:21 2026. Slay 💅✨