1wxGUI.vdigit(1) GRASS GIS User's Manual wxGUI.vdigit(1)
2
7 The vector digitizer is a wxGUI component intended for interactive
8 editing and digitizing vector maps (see v.edit for non-interactive vec‐
9 tor editing GRASS capabilities).
10 Note that only vector maps stored or generated in the current mapset
12 can be opened for editing.
13 The digitizer allows editing of 2D vector features (points, lines, cen‐
15 troids, boundaries, and areas).
16 Vector features can be selected by mouse (bounding box or simply by
18 mouse click, see select threshold in SettingsâGeneralâSelect
19 threshold), or by query (eg. by line length, see SettingsâQuery
20 Tool).
21 STARTING THE DIGITIZER
23 The vector digitizer can be launched from Map Display toolbar by se‐
24 lecting "Digitize" from Tools combobox. Vector map is selectable for
25 editing from Digitizer toolbar ("Select vector map" combobox, note that
26 only vector maps from the current layer tree in Layer Manager are
27 listed). The vector digitizer can alternatively be activated from the
28 contextual menu in the Layer Manager by selecting "Start editing" on
29 selected vector map in the layer tree, or directly from the Layer Man‐
30 ager toolbar . The vector digitizer also can also be launched from the
31 command line as a stand-alone application g.gui.vdigit.
32 CREATING A NEW VECTOR MAP
34 A new vector map can be easily created from the digitizer toolbar by
35 selecting "New vector map" in "Select vector map" combobox. A new vec‐
36 tor map is created, added to the current layer tree in Layer Manager
37 and opened for editing. "Select vector map" combobox in the digitizer
38 toolbar also allows easily switching between vector maps to be edited.
39 EDITING AN EXISTING VECTOR MAP
41 An existing vector map selected in the digitizer toolbar in the "Select
42 vector map" combobox. This map is then opened for editing and added to
43 the current layer tree in the Layer Manager. This "Select vector map"
44 combobox in the digitizer toolbar also allows to easily switch between
45 vector maps to be edited.
46 USING A RASTER BACKGROUND MAP
48 In order to digitize from a raster map, simply load the map into the
49 Map Display using the Layer Manager. Then start digitizing, see below
50 for details.
51 USING A VECTOR BACKGROUND MAP
53 The vector digitizer allows you to select a "background" vector map.
54 Loading it within the digitizer is different from simply loading it via
55 Layer Manager since direct interaction with single vector features then
56 becomes possible.
57 Vector features may be copied from the background map by "Copy features
58 from (background) vector map" tool from the "Additional tools" of the
59 digitizer toolbar. Newly digitized vector features are snapped in the
60 given threshold to the features from the background map.
61 DIGITIZER TOOLBAR
63 Â Digitize new point
64 Add new point to vector map and optionally define its attributes
65 (Ctrl+P).
66 Â Digitize new line
68 Add new line to vector map and optionally define its attributes
69 (Ctrl+L).
70 Â Digitize new boundary
72 Add new boundary to vector map and optionally define its attributes
73 (Ctrl+B).
74 Â Digitize new centroid
76 Add new centroid to vector map and optionally define its attributes
77 (Ctrl+C).
78 Â Digitize new area
80 Add new area (closed boundary and one centroid inside) to vector
81 map and optionally define its attributes (Ctrl+A).
82 Â Move vertex
84 Move selected vertex of linear feature. Thus shape of linear fea‐
85 ture is changed (Ctrl+G).
86 Â Add vertex
88 Add new vertex to selected linear feature (shape not changed)
89 (Ctrl+V).
90 Â Remove vertex
92 Remove selected vertex from linear feature (Ctrl+X). Thus shape of
93 selected feature can be changed.
94 Â Edit line/boundary
96 Edit selected linear feature, add new segments or remove existing
97 segments of linear feature (Ctrl+E).
98 Â Move feature(s)
100 Move selected vector features (Ctrl+M.) Selection can be done by
101 mouse or by query.
102 Â Delete feature(s)
104 Delete selected vector features (point, line, centroid, or bound‐
105 ary) (Ctrl+D). Selection can be done by mouse or by query.
106 Â Delete areas(s)
108 Delete selected vector areas (Ctrl+F). Selection can be done by
109 mouse or by query.
110 Â Display/update categories
112 Display categories of selected vector feature (Ctrl+J). Category
113 settings can be modified, new layer/category pairs added or already
114 defined pairs removed.
115 Â Display/update attributes
117 Display attributes of selected vector feature (based on its cate‐
118 gory settings) (Ctrl+K). Attributes can be also modified. Same
119 functionality is accessible from Main toolbar "Query vector map
120 (editable mode)".
121 Â Additional tools
123 • Break selected lines/boundaries at intersection
125 Split given vector line or boundary into two lines on given po‐
126 sition (based on v.clean, tool=break).
127 • Connect two selected lines/boundaries
129 Connect selected lines or boundaries, the first given line is
130 connected to the second one. The second line is broken if nec‐
131 essary on each intersection. The lines are connected only if
132 distance between them is not greater than snapping threshold
133 value.
134 • Copy categories
136 Copy category settings of selected vector feature to other vec‐
137 tor features. Layer/category pairs of source vector features
138 are appended to the target feature category settings. Existing
139 layer/category pairs are not removed from category settings of
140 the target features.
141 • Copy features from (background) vector map
143 Make identical copy of selected vector features. If a back‐
144 ground vector map has been selected from the Layer Manager,
145 copy features from background vector map, not from the cur‐
146 rently modified vector map.
147 • Copy attributes
149 Duplicate attributes settings of selected vector feature to
150 other vector features. New category(ies) is appended to the
151 target feature category settings and attributes duplicated
152 based on category settings of source vector features. Existing
153 layer/category pairs are not removed from category settings of
154 the target features.
155 • Feature type conversion
157 Change feature type of selected geometry features. Points are
158 converted to centroids, centroids to points, lines to bound‐
159 aries and boundaries to lines.
160 • Flip selected lines/boundaries
162 Flip direction of selected linear features (lines or bound‐
163 aries).
164 • Merge selected lines/boundaries
166 Merge (at least two) selected vector lines or boundaries. The
167 geometry of the merged vector lines can be changed. If the sec‐
168 ond line from two selected lines is in opposite direction to
169 the first, it will be flipped. See also module v.build.poly‐
170 lines.
171 • Snap selected lines/boundaries (only to nodes)
173 Snap vector features in given threshold. See also module
174 v.clean. Note that this tool supports only snapping to nodes.
175 Snapping to vector features from background vector map is not
176 currently supported.
177 • Split line/boundary
179 Split selected line or boundary on given position.
180 • Query tool
182 Select vector features by defining a threshold for min/max
183 length value (linear features or dangles).
184 • Z-bulk labeling of 3D lines
186 Assign z coordinate values to 3D vector lines in bounding box.
187 This is useful for labeling contour lines.
188 Â Undo
190 Undo previous operations (Ctrl+Z).
191 Â Redo
193 Redo previous operations (Ctrl+Y).
194 Â Settings
196 Digitizer settings (Ctrl+T).
197 Â Show help
199 Show help page for the Digitizer (Ctrl+H).
200 Â Quit digitizing tool
202 Changes in vector map can be optionally discarded when digitizing
203 session is quited (Ctrl+Q).
204
206 Mouse button functions:
207 Left - select or deselect features
209 Control+Left - cancel action or undo vertex when digitizing lines
211 Right - confirm action
213 Dead (deleted) features are only marked as ’dead’ in the geometry file
215 but remain there and occupy space. Any vector module used afterwards on
216 this vector map which really reads and writes vector geometry (so not
217 g.copy) will write only features which are ’alive’.
218 Added or modified vector features are snapped to existing vector fea‐
220 tures (SettingsâGeneralâSnapping). To disable snapping set the
221 snapping threshold to ’0’.
222 If the digitizer crashes for some reason, the changes are automatically
224 saved. Broken topology can be repaired by running v.build.
225 GRASS GIS uses a topological vector format, meaning that a common
227 boundary of two polygons is only stored once. When digitizing polygons
228 it is thus important to be able to only draw each boundary once. When
229 drawing a polygon adjacent to an existing polygon, one has to first
230 split the existing boundary at the points where the new boundary will
231 be attached. Snapping should be set to ensure that the new boundaries
232 are automatically attached to the chosen points.
233
235 • GRASS Vedit Library
236 • Vector Database Management (Wiki page)
238
240 wxGUI
241 wxGUI components
242 v.edit, v.category, v.build, g.gui.rdigit, wxGUI.rdigit
244 See also the WxGUI Vector Digitizer Wiki page including video tutori‐
246 als.
247
249 Martin Landa, FBK-irst (2007-2008), Trento, Italy, and Czech Technical
250 University in Prague, Czech Republic
251
253 Available at: wxGUI Vector Digitizer source code (history)
254 Accessed: Saturday Oct 28 18:20:09 2023
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259 © 2003-2023 GRASS Development Team, GRASS GIS 8.3.1 Reference Manual
261GRASS 8.3.1 wxGUI.vdigit(1)