Note: A new GRASS GIS stable version has been released: GRASS GIS 7. Go directly to the new manual page here
The vector digitizer is
a wxGUI component intended for
interactive editing vector maps
(see v.edit for non-interactive
vector editing GRASS capabilities).
The digitizer supports editing of 2D vector features (points, lines, centroids,
boundaries, and area).
Vector features can be selected using mouse or by query (e.g. minimal
vector line length). Vector features can be selected by bounding box
or simply by mouse click (based on 'Settings->General->Select
Vector digitizer can be activated from Main toolbar in Map Display by
selecting "Digitize" from "Tools" combobox. Vector map to be edited
can be afterwards selected from digitizer toolbar ("Select vector map"
combobox, note that only vector maps from the current layer tree in Layer
Manager are available).
Vector digitizer can be alternatively also activated from contextual
menu in Layer Manager by selecting "Start editing" on selected vector
map in the layer tree.
New vector map can be easily created from digitizer toolbar by
selecting "New vector map" in "Select vector map" combobox. A new
vector map is created, added to the current layer tree in Layer
Manager and opened for editing. "Select vector map" combobox in
digitizer toolbar also allows switching easily between vector maps to be
The wxGUI vector digitizer draws all maps in the Layer Manager in the Map
Display window; in addition, the digitizer also recognizes a special
"background" vector map. This map is selected from the Layer Manager by
right-clicking on the map and selecting "Use as Background Map" from the
contextual menu. The features of the background map may then be copied into
the currently edited vector map using the "Copy features from (background)
vector map" button in the "Additional Tools" menu on the Digitzer Toolbar.
Digitize new point
- Add new point to vector map and optionally define its
Digitize new line
- Add new line to vector map and optionally define its
Digitize new boundary
- Add new boundary to vector map and optionally define its
Digitize new centroid
- Add new centroid to vector map and optionally define its
Digitize new area
- Add new area (closed boundary and one centroid inside) to vector
map and optionally define its attributes.
- Move selected vertex of linear feature. Thus shape of linear
feature is changed.
- Add new vertex to selected linear feature (shape not
- Remove selected vertex from linear feature. Thus shape of selected
feature can be changed.
- Edit selected linear feature, add new segments or remove
existing segments of linear feature.
- Move selected vector features. Selection can be done by mouse or
- Delete selected vector features (point, line, centroid, or
boundary). Selection can be done by mouse or by query.
- Display categories of selected vector feature. Category settings
can be modified, new layer/category pairs added or already defined pairs
- Display attributes of selected vector feature (based on its
category settings). Attributes can be also modified. Same
functionality is accessible from Main toolbar "Query vector map
- Break selected lines/boundaries at intersection
given vector line or boundary into two lines on given position
(based on v.clean,
- Connect two selected lines/boundaries
lines or boundaries, the first given line is connected to the
second one. The second line is broken if necessary on each intersection.
The lines are connected only if distance between them is not greater
than snapping threshold value.
- Copy categories
Copy category settings of
selected vector feature to other vector
features. Layer/category pairs of source vector features are
appended to the target feature category settings. Existing
layer/category pairs are not removed from category settings of
the target features.
- Copy features from (background) map
Make identical copy of
selected vector features. If a background vector map has been
selected from the Layer Manager, copy features from background
vector map, not from the currently modified vector map.
- Copy attributes
Duplicate attributes settings of
selected vector feature to other vector features. New
category(ies) is appended to the target feature category
settings and attributes duplicated based on category settings
of source vector features. Existing layer/category pairs are
not removed from category settings of the target
- Feature type conversion
Change feature type of selected
geometry features. Points are converted to centroids,
centroids to points, lines to boundaries and boundaries to
- Flip selected lines/boundaries
Flip direction of
selected linear features (lines or boundaries).
- Merge selected lines/boundaries
Merge (at least two)
selected vector lines or boundaries. The geometry of the
merged vector lines can be changed. If the second line from
two selected lines is in opposite direction to the first, it
will be flipped. See also
- Snap selected lines/boundaries (only to nodes)
vector features in given threshold. See also
module v.clean. Note that
this tool supports only snapping to nodes. Snapping to vector
features from background vector map is not currently
- Split line/boundary
Split selected line or boundary on
- Query tool
Select vector features by defining a threshold for
min/max length value (linear features or dangles).
- Z-bulk labeling of 3D lines
Assign z coordinate values to 3D
vector lines in bounding box. This is useful for labeling contour lines.
- Undo previous operations.
- Dialog for vector digitizer settings.
Quit digitizing tool
- Changes in vector map can be optionally discarded when
digitizing session is quited.
- Mouse button Functions:
- Left - select/deselect features
- Control+Left - cancel action/undo vertex
- Right - confirm action
Dead (deleted) are internally only marked in the geometry file
as 'dead' but it remains there and occupies space. Any vector module
used afterwards on this vector map which really reads and writes
vector geometry (so not g.copy)
will writes only features which are 'alive'.
Added or modified vector features are snapped to
existing vector features (Settings→General→Snapping). To
disable snapping set the snapping threshold to '0'.
If the digitizer crashes for some reason you can repair the vector map
which was left open with the v.build module.
Martin Landa, FBK-irst (2007-2008), Trento, Italy, and Czech Technical
University in Prague, Czech Republic
$Date: 2013-02-15 14:04:18 -0800 (Fri, 15 Feb 2013) $
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