A coordinate-based data model that represents geographic features as points, lines, and polygons.
0
votes
1answer
441 views
Add labels above the lines in OpenLayers
How to add labels above the lines?
Labels are added as follows:
var styleMarkersLabels = new OpenLayers.Style( // стили для надписей узлов
{
strokeWidth: 2,
...
2
votes
1answer
555 views
How to export vectors from QGIS to MapInfo?
I am trying to save some vector lines that I made in QGIS (1.8 Lisboa) to a format that can be added to MapInfo Professional 6.0 (ancient version I know..).
When I save the vector to a Mapinfo ...
6
votes
3answers
1k views
How to find and merge duplicate points?
I have two point shapefiles: Red and Blue. Each point shapefile has a z value which represents a radius (i.e. represented as buffers in the example). A duplicate point is defined as a point that ...
0
votes
0answers
31 views
interpolation layer stops adding vertex
in qgis i m using vector layer and adding the vertex in interpolation layer but it only creats two point layer and the vertex are not added.
provider= layer.dataProvider()
if len(self.points)==2:
...
3
votes
1answer
161 views
Halo in OpenLayers (Line, Vector)
How to make a halo around the line of one pixel? For example,
line (vector) hase blue color and its frame (one pixel) the black color.
Thanks!
5
votes
1answer
225 views
Vector Building Footprint Resources - Tokyo
I typically know where to look for this data in the United States, but I'm at a loss when looking for building footprint shapefiles abroad. I thought I could find what I was looking for with Open ...
3
votes
1answer
195 views
How to access the icon of a feature retrieved from text in a vector-layer?
I`m using OpenLayers to show POIs on a map. These POIs are loaded from a textfile and I`m using a Vector Layer to get it onto the map - works great.
Now I want to use the cluster strategy to have ...
2
votes
2answers
114 views
Determine the furthest driving distance from a road layer to the nearest point of a point layer using OSM/QGIS
In a specific geographic area, I have a road layer and roughly 30 points dispersed around the geographic area as part of a point layer. Both layers are in SHP and PostGIS formats. The records from the ...
2
votes
3answers
743 views
Change zIndex of Vectors in openlayers
I have a bunch of linestring features on a vector layer. Some of them overlap. If I trigger the hover event on those features, I want them be in front.
I did find some functions to set the z-index of ...
1
vote
1answer
301 views
openlayers trigger hover event
I have a bunch of tracks on screen in a vector layer. I used some hover and select styles in the layer styleMap and these styles are properly triggered by:
var highlightCtrl = new ...
2
votes
1answer
358 views
Loading Raster and vector data In MapGuide using Maestro
I am new to Mapguide , working on it for my summer Internship.I have Installed it perfectly.
Now the task is to load vector data and Raster data in map Guide (mainly have to load *.shp files and *.tif ...
1
vote
1answer
312 views
How to reproject vector datasets in ArcMap?
I want to change one Personal Geo-database projection to another. Kindly give me instructions to re-project vector data.
2
votes
5answers
987 views
vector layer co-ordinate extraction QGIS
I add my own road vector data on top of Google map using open layers plugin with QGIS. The vector layer is generated using PostgreSQL DB.
Is there any way to extract co-ordinates of a road segment ?
...
2
votes
1answer
2k views
Calculating the minimum distance between points and polygons in QGIS
I have two vector layers: one point and one polygon and I want to calculate the minimum distance of each point from the polygons (ie the distance from the closest point of the closest polygon). Is ...
1
vote
2answers
193 views
Its possible to catch ServiceException in Openlayers?
Im trying to catch exception in OpenLayers using vector layers in conjunction with http protocol, its possible to intercept an ServiceException from geoserver ... it will be great to display some ...
3
votes
1answer
752 views
OpenLayers - Vector Layer and Google Maps - vector layer and google layers don't seem to be in sync when zooming on Chrome
I am working with a Google Layer and a vector layer in OpenLayers. I was wondering if anyone else noticed any problems with Chrome displaying Google Maps layers on OpenLayers? It seems that when I ...
2
votes
1answer
279 views
Vector layer feature destroys after geometry transform
I want to get drawn polygon coordinates.
var myLatLonSquare = vectorLayer.features[0].geometry.transform(map.getProjectionObject(),
new OpenLayers.Projection("EPSG:4326"));
...
1
vote
2answers
1k views
Some Help to select some features from a vector layer
I have a vector layer (kml) that has some point with scientific name of plants and animals, some description of the place where the people saw them and the coordinates.
Basically the table associated ...
4
votes
1answer
1k views
Trouble exporting from QGIS to Illustrator
I am having trouble getting my files to transfer or export to a vector file. When I open the file in Adobe illustrator there is a lot of information missing. I have tried to "save selection as a ...
3
votes
2answers
310 views
Unable to select Vector Layer
I am using the following example, to select a vector layer feature on click. The example demonstrates Highlighting and selecting the layer. I was able to successfully implement the Highlighting of the ...
12
votes
2answers
334 views
Is there any open-source object-oriented GIS?
Most GIS are layer based. But I am looking for open-source object-oriented GIS. Is there any out there?
By object-oriented I mean logical data model for vector GIS. Here's explanation of my ...
4
votes
1answer
194 views
Generate centroids for vector polygons based on raster and land-use data using QGIS
Although QGIS has the ability to generate centroids for polygons, I am not sure how to generate centroids based on land-use development using raster data.
Here's an example of what I'm trying to do:
...
0
votes
4answers
1k views
OpenLayers (allOverlays): Vector layer not rendered without raster layer beneath it
This is another newbie question. I'm trying to create a map using OpenLayers that comprises only of vector layers from a WFS server. However, I'm thwarted because my vector layer won't render unless ...
2
votes
2answers
549 views
Multiple Maps with Styles not working in OpenLayers
I have created 2 maps(within 2 in a same page) along with their respective style maps.
Both maps are having vector layers along with "LineString" geometry... added into them.
Both style maps are ...
1
vote
1answer
260 views
Merge two maps with OR operation in GRASS
I have two vector maps. The two maps cover the same area but are split up into polygons differently (i.e. if you were to imagine one map placed above the other, the lines defining the polygons would ...
1
vote
1answer
131 views
v.dissolve renames the attribute table column and does not produce a dbf
When I run v.dissolve on my vector...
v.dissolve --o input=pass2@mapset1 layer=1 column=fttcp output=pass3
The dissolving appears to work but the column name in the attribute table has changed from ...
0
votes
0answers
168 views
Power line and/or power station vector (shapefile) data in Turkey
Looking for transmission power line / power station vector (shapefile) data in the country of Turkey. KML/KMZ files would also work.
Found great vector data here yesterday for roads, rivers, etc: ...
4
votes
1answer
373 views
fTools-Error: “…invalid geometry…”
I want to intersect contours with polygon like in the image below. But i got this error:
Warnings:
GEOS geoprocessing error: One or more input features have invalid geometry.
Some output geometries ...
2
votes
3answers
552 views
Cut many lines with many polygons: Too much for my CPU/RAM?
I have a line-shp (80mb) and a polygon-shp (5mb) and want to intersect them. In result, the lines (contours) should be cut by the polygons.
After using one of the tools "Vector -> Geoprocessing ...
1
vote
1answer
349 views
Splitting lines at a specified distance
Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
1
vote
2answers
135 views
How to select only areas bigger than x acres?
I would like to create a new shapefile from another area shapefile. The new shapefile should only contain all areas that are bigger than 5 acres (10.000 m²).
How do I do this?
1
vote
2answers
717 views
How to get vector feature information (distance and extent ) on OpenLayers
I have basic WMS layer and vector layer in openlayers. Using EditingToolbar i can draw some features as shown below
Then I want to get some information (like distance and extent) of drawn features ...
2
votes
3answers
992 views
Openlayers: Copy shape layer in a vector layer
I have a web-gis application based on openlayers and geoserver.
I need to modify a shape layer. I'm able to show the shape using the OpenLayers.Layer.WMS method. In fact i published the shape in ...
1
vote
1answer
160 views
Why are layers not lining up with others with the same CRS? [closed]
I am creating a project on the UK and have downloaded various shapefiles. When I add a vector layer they are coming up as if they are not lining up. Some layers are nicely on top of each other with ...
1
vote
0answers
109 views
Polygon symmetry detection
I was wondering if there was any way to create main axis (axis of symmetry) lines for polygons.
I have polygons that represents buildings.
I will want to find main axes (axis of symmetry) for those ...
2
votes
1answer
78 views
Keeping a vector layer always on top
I want to know how to keep a layer always on top of other layers! After adding a vector layer ( QgisInterface->addVectorLayer ), I want that layer to always be displayed on top of layers added later. ...
4
votes
4answers
1k views
How to split a vector in equal smaller parts in QGIS or similar?
i want to divide a shapefile with many tiles into a lot of smaller tiles.
I am searching for a smart solution, because manual edits are out of questions
Anyone can help or know a nice function?
1
vote
3answers
1k views
What is the problem with the merge shapefiles tool in QGIS?
I'm having trouble merging shapefiles in QGIS. I'm using plugin ftools 0.6.1 and I get this:
Any workarounds someone may know of?
Thanks
2
votes
2answers
825 views
How to create dynamic map images?
I have map images of my local ward (Areas geo-referenced and drawn using QGIS and Adobe illustrator. Now these maps are in .png format (Raster images). It's not a tile linked to some mapserver such as ...
4
votes
1answer
351 views
Analysing Information By Vector Grid
I have two vector line datasets and wish to compare the line lengths. While I have already compared the sum of the lengths, I'd like to conduct further analysis down to 250m, possibly lower.
I'm ...
3
votes
1answer
268 views
Sum up area left “underneath” polygons in QGIS?
I have an area shape layer and multiple other area shape layers. Now I would like to calculate how much space (square kilometers or percentage of area) of the polygons of this area layer is NOT ...
2
votes
1answer
392 views
Why does intersect not calculate polygon areas?
this is strange: I intersected 2 shape-files and the resulting shape does not contain the Shape_Area and Shape_Length of the intersected polygons. Instead the field Shape_Area contains the ...
5
votes
3answers
5k views
How to convert a vector layer to raster?
In qgis in the raster menu there is an item "convert vector to raster".
This behaves strangely - I do not understand how it is supposed to work.
I can select a vector file, an attribute and an ...
4
votes
3answers
1k views
How to combine information from raster and vector layers?
in QGIS I have 1 raster-layer (elevation) and 1 vector-layer (administrative units).
Now I would like to be able to query one of the administrative units and see the mean and min/max of the elevation ...
4
votes
2answers
338 views
Is it possible to generate a vector polygon from a polygon on a raster image?
I have a raster map which I have extracted from a government report providing flood extent return frequencies. I want to 'snatch' these flood extent polygons (i.e. convert to vector) and I was ...
4
votes
2answers
1k views
How to clip a vector feature to the extent of an existing raster dataset using arcpy
I have a clipped raster dataset with polylines (from the contour tool) overlayed (see attached). I am trying to clip the polylines to the extent of the raster dataset, which seems simple enough, but ...
1
vote
1answer
233 views
Polymaps / Tilestache tiling grid mismatch
I have set up a basic PostGIS / Tilestache / gunicorn / nginx / Polymaps test environment, rendering my dataset from PostGIS to GeoJSON and shipping it out to be rendered in Polymaps.
That works ...
2
votes
1answer
353 views
Select vectors overlapping a raster
I have a raster layer with travel times from a specified point in my city's downtown. What I'd like to do is select all of the census blocks that lie at least partially within 45 minutes of downtown ...
2
votes
2answers
232 views
How OpenStreetMap data layer works?
OSM map has a data layer and an information panel. How is it implemented? What is a type of the layer and URL of vector data source? How information panel works?
Thanks for all!
7
votes
1answer
267 views
What is the best way to represent bridges using a point vector layer in QGIS?
I'm working on a hiking/biking maps of trails in the woods which sometimes have bridges that need to be shown on the map. I'm trying to figure out the best way to capture and represent them using QGIS ...
