1wxGUI.vdigit(1) Grass 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 Settings→Gen‐
19 eral→Select threshold), or by query (eg. by line length, see Set‐
20 tings→Query Tool).
21 STARTING THE DIGITIZER
23 The vector digitizer can be launched from Map Display toolbar by
24 selecting "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 Digitize new point
64 Add new point to vector map and optionally define its attributes.
65 Digitize new line
67 Add new line to vector map and optionally define its attributes.
68 Digitize new boundary
70 Add new boundary to vector map and optionally define its
71 attributes.
72 Digitize new centroid
74 Add new centroid to vector map and optionally define its
75 attributes.
76 Digitize new area
78 Add new area (closed boundary and one centroid inside) to vector
79 map and optionally define its attributes.
80 Move vertex
82 Move selected vertex of linear feature. Thus shape of linear fea‐
83 ture is changed.
84 Add vertex
86 Add new vertex to selected linear feature (shape not changed).
87 Remove vertex
89 Remove selected vertex from linear feature. Thus shape of selected
90 feature can be changed.
91 Edit line/boundary
93 Edit selected linear feature, add new segments or remove existing
94 segments of linear feature.
95 Move feature(s)
97 Move selected vector features. Selection can be done by mouse or by
98 query.
99 Delete feature(s)
101 Delete selected vector features (point, line, centroid, or bound‐
102 ary). Selection can be done by mouse or by query.
103 Delete areas(s)
105 Delete selected vector areas. Selection can be done by mouse or by
106 query.
107 Display/update categories
109 Display categories of selected vector feature. Category settings
110 can be modified, new layer/category pairs added or already defined
111 pairs removed.
112 Display/update attributes
114 Display attributes of selected vector feature (based on its cate‐
115 gory settings). Attributes can be also modified. Same functional‐
116 ity is accessible from Main toolbar "Query vector map (editable
117 mode)".
118 Additional tools
120 · Break selected lines/boundaries at intersection
122 Split given vector line or boundary into two lines on given
123 position (based on v.clean, tool=break).
124 · Connect two selected lines/boundaries
126 Connect selected lines or boundaries, the first given line is
127 connected to the second one. The second line is broken if nec‐
128 essary on each intersection. The lines are connected only if
129 distance between them is not greater than snapping threshold
130 value.
131 · Copy categories
133 Copy category settings of selected vector feature to other vec‐
134 tor features. Layer/category pairs of source vector features
135 are appended to the target feature category settings. Existing
136 layer/category pairs are not removed from category settings of
137 the target features.
138 · Copy features from (background) vector map
140 Make identical copy of selected vector features. If a back‐
141 ground vector map has been selected from the Layer Manager,
142 copy features from background vector map, not from the cur‐
143 rently modified vector map.
144 · Copy attributes
146 Duplicate attributes settings of selected vector feature to
147 other vector features. New category(ies) is appended to the
148 target feature category settings and attributes duplicated
149 based on category settings of source vector features. Existing
150 layer/category pairs are not removed from category settings of
151 the target features.
152 · Feature type conversion
154 Change feature type of selected geometry features. Points are
155 converted to centroids, centroids to points, lines to bound‐
156 aries and boundaries to lines.
157 · Flip selected lines/boundaries
159 Flip direction of selected linear features (lines or bound‐
160 aries).
161 · Merge selected lines/boundaries
163 Merge (at least two) selected vector lines or boundaries. The
164 geometry of the merged vector lines can be changed. If the sec‐
165 ond line from two selected lines is in opposite direction to
166 the first, it will be flipped. See also module v.build.poly‐
167 lines.
168 · Snap selected lines/boundaries (only to nodes)
170 Snap vector features in given threshold. See also module
171 v.clean. Note that this tool supports only snapping to nodes.
172 Snapping to vector features from background vector map is not
173 currently supported.
174 · Split line/boundary
176 Split selected line or boundary on given position.
177 · Query tool
179 Select vector features by defining a threshold for min/max
180 length value (linear features or dangles).
181 · Z-bulk labeling of 3D lines
183 Assign z coordinate values to 3D vector lines in bounding box.
184 This is useful for labeling contour lines.
185 Undo
187 Undo previous operations.
188 Redo
190 Redo previous operations.
191 Settings
193 Digitizer settings.
194 Quit digitizing tool
196 Changes in vector map can be optionally discarded when digitizing
197 session is quited.
198
200 Mouse button functions:
201 Left - select or deselect features
203 Control+Left - cancel action or undo vertex when digitizing lines
205 Right - confirm action
207 Dead (deleted) features are only marked as ’dead’ in the geometry file
209 but remain there and occupy space. Any vector module used afterwards on
210 this vector map which really reads and writes vector geometry (so not
211 g.copy) will write only features which are ’alive’.
212 Added or modified vector features are snapped to existing vector fea‐
214 tures (Settings→General→Snapping). To disable snapping set
215 the snapping threshold to ’0’.
216 If the digitizer crashes for some reason, the changes are automatically
218 saved. Broken topology can be repaired by running v.build.
219 GRASS GIS uses a topological vector format, meaning that a common
221 boundary of two polygons is only stored once. When digitizing polygons
222 it is thus important to be able to only draw each boundary once. When
223 drawing a polygon adjacent to an existing polygon, one has to first
224 split the existing boundary at the points where the new boundary will
225 be attached. Snapping should be set to ensure that the new boundaries
226 are automatically attached to the chosen points.
227
229 · GRASS Vedit Library
230 · Vector Database Management (Wiki page)
232
234 wxGUI
235 wxGUI components
236 v.edit, v.category, v.build, wxGUI.rdigit
238 See also the WxGUI Vector Digitizer Wiki page including video tutori‐
240 als.
241
243 Martin Landa, FBK-irst (2007-2008), Trento, Italy, and Czech Technical
244 University in Prague, Czech Republic
245 $Date: 2018-10-14 21:39:26 +0200 (Sun, 14 Oct 2018) $
247
249 Available at: wxGUI Vector Digitizer source code (history)
250 Main index | GUI index | Topics index | Keywords index | Graphical
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253 © 2003-2019 GRASS Development Team, GRASS GIS 7.6.0 Reference Manual
255GRASS 7.6.0 wxGUI.vdigit(1)