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 at‐
73 tributes.
74 Â Digitize new centroid
76 Add new centroid to vector map and optionally define its at‐
77 tributes.
78 Â Digitize new area
80 Add new area (closed boundary and one centroid inside) to vector
81 map and optionally define its attributes.
82 Â Move vertex
84 Move selected vertex of linear feature. Thus shape of linear fea‐
85 ture is changed.
86 Â Add vertex
88 Add new vertex to selected linear feature (shape not changed).
89 Â Remove vertex
91 Remove selected vertex from linear feature. Thus shape of selected
92 feature can be changed.
93 Â Edit line/boundary
95 Edit selected linear feature, add new segments or remove existing
96 segments of linear feature.
97 Â Move feature(s)
99 Move selected vector features. Selection can be done by mouse or by
100 query.
101 Â Delete feature(s)
103 Delete selected vector features (point, line, centroid, or bound‐
104 ary). Selection can be done by mouse or by query.
105 Â Delete areas(s)
107 Delete selected vector areas. Selection can be done by mouse or by
108 query.
109 Â Display/update categories
111 Display categories of selected vector feature. Category settings
112 can be modified, new layer/category pairs added or already defined
113 pairs removed.
114 Â Display/update attributes
116 Display attributes of selected vector feature (based on its cate‐
117 gory settings). Attributes can be also modified. Same functional‐
118 ity is accessible from Main toolbar "Query vector map (editable
119 mode)".
120 Â Additional tools
122 • Break selected lines/boundaries at intersection
124 Split given vector line or boundary into two lines on given po‐
125 sition (based on v.clean, tool=break).
126 • Connect two selected lines/boundaries
128 Connect selected lines or boundaries, the first given line is
129 connected to the second one. The second line is broken if nec‐
130 essary on each intersection. The lines are connected only if
131 distance between them is not greater than snapping threshold
132 value.
133 • Copy categories
135 Copy category settings of selected vector feature to other vec‐
136 tor features. Layer/category pairs of source vector features
137 are appended to the target feature category settings. Existing
138 layer/category pairs are not removed from category settings of
139 the target features.
140 • Copy features from (background) vector map
142 Make identical copy of selected vector features. If a back‐
143 ground vector map has been selected from the Layer Manager,
144 copy features from background vector map, not from the cur‐
145 rently modified vector map.
146 • Copy attributes
148 Duplicate attributes settings of selected vector feature to
149 other vector features. New category(ies) is appended to the
150 target feature category settings and attributes duplicated
151 based on category settings of source vector features. Existing
152 layer/category pairs are not removed from category settings of
153 the target features.
154 • Feature type conversion
156 Change feature type of selected geometry features. Points are
157 converted to centroids, centroids to points, lines to bound‐
158 aries and boundaries to lines.
159 • Flip selected lines/boundaries
161 Flip direction of selected linear features (lines or bound‐
162 aries).
163 • Merge selected lines/boundaries
165 Merge (at least two) selected vector lines or boundaries. The
166 geometry of the merged vector lines can be changed. If the sec‐
167 ond line from two selected lines is in opposite direction to
168 the first, it will be flipped. See also module v.build.poly‐
169 lines.
170 • Snap selected lines/boundaries (only to nodes)
172 Snap vector features in given threshold. See also module
173 v.clean. Note that this tool supports only snapping to nodes.
174 Snapping to vector features from background vector map is not
175 currently supported.
176 • Split line/boundary
178 Split selected line or boundary on given position.
179 • Query tool
181 Select vector features by defining a threshold for min/max
182 length value (linear features or dangles).
183 • Z-bulk labeling of 3D lines
185 Assign z coordinate values to 3D vector lines in bounding box.
186 This is useful for labeling contour lines.
187 Â Undo
189 Undo previous operations.
190 Â Redo
192 Redo previous operations.
193 Â Settings
195 Digitizer settings.
196 Â Quit digitizing tool
198 Changes in vector map can be optionally discarded when digitizing
199 session is quited.
200
202 Mouse button functions:
203 Left - select or deselect features
205 Control+Left - cancel action or undo vertex when digitizing lines
207 Right - confirm action
209 Dead (deleted) features are only marked as ’dead’ in the geometry file
211 but remain there and occupy space. Any vector module used afterwards on
212 this vector map which really reads and writes vector geometry (so not
213 g.copy) will write only features which are ’alive’.
214 Added or modified vector features are snapped to existing vector fea‐
216 tures (SettingsâGeneralâSnapping). To disable snapping set the
217 snapping threshold to ’0’.
218 If the digitizer crashes for some reason, the changes are automatically
220 saved. Broken topology can be repaired by running v.build.
221 GRASS GIS uses a topological vector format, meaning that a common
223 boundary of two polygons is only stored once. When digitizing polygons
224 it is thus important to be able to only draw each boundary once. When
225 drawing a polygon adjacent to an existing polygon, one has to first
226 split the existing boundary at the points where the new boundary will
227 be attached. Snapping should be set to ensure that the new boundaries
228 are automatically attached to the chosen points.
229
231 • GRASS Vedit Library
232 • Vector Database Management (Wiki page)
234
236 wxGUI
237 wxGUI components
238 v.edit, v.category, v.build, g.gui.rdigit, wxGUI.rdigit
240 See also the WxGUI Vector Digitizer Wiki page including video tutori‐
242 als.
243
245 Martin Landa, FBK-irst (2007-2008), Trento, Italy, and Czech Technical
246 University in Prague, Czech Republic
247
249 Available at: wxGUI Vector Digitizer source code (history)
250 Accessed: Saturday Jan 21 21:17:59 2023
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255 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
257GRASS 8.2.1 wxGUI.vdigit(1)