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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 threshold' value).

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 edited.

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 attributes.
  Digitize new line
Add new line to vector map and optionally define its attributes.
  Digitize new boundary
Add new boundary to vector map and optionally define its attributes.
  Digitize new centroid
Add new centroid to vector map and optionally define its attributes.
  Digitize new area
Add new area (closed boundary and one centroid inside) to vector map and optionally define its attributes.
  Move vertex
Move selected vertex of linear feature. Thus shape of linear feature is changed.
  Add vertex
Add new vertex to selected linear feature (shape not changed).
  Remove vertex
Remove selected vertex from linear feature. Thus shape of selected feature can be changed.
  Edit line/boundary
Edit selected linear feature, add new segments or remove existing segments of linear feature.
  Move feature(s)
Move selected vector features. Selection can be done by mouse or by query.
  Delete feature(s)
Delete selected vector features (point, line, centroid, or boundary). Selection can be done by mouse or by query.
  Display/update categories
Display categories of selected vector feature. Category settings can be modified, new layer/category pairs added or already defined pairs removed.
  Display/update attributes
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 (editable mode)".
  Additional tools
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 module.



wxGUI components

v.edit, v.category,

See also the wiki page including video tutorials.


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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