A coordinate-based data model that represents geographic features as points, lines, and polygons.
2
votes
2answers
135 views
How to find the middle point of a line in QGIS
I am trying to locate the coordinates of the middle point of a line feature in QGIS. I tried searching online but can't seem to find an easy way to do this.
2
votes
3answers
555 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 ...
2
votes
1answer
2k views
How can I update the label of a Polygon Vector after it has been drawn?
I am quite new to OpenLayers. Right now, I have a polygon vector with some styling applied and a label.
var style = $.extend(true, {}, OpenLayers.Feature.Vector.style['default']);
style.pointRadius ...
2
votes
1answer
72 views
How to best execute the same query on many different vector layers?
I have some vector layers in my project and I need to separate the polygones by area (I need a copy of all shapes > 2ha). I know how to do this for each separate layer (query) but is the a tool to do ...
2
votes
2answers
153 views
Creating seperate layers out of one big polygon shape by using attributes
I try to explain may problem. I have a big polygon shape (> 200 fields). I have the owners of these fields in a column. I need the seperated shapes for each owner. Is there a tool to do that?
Is it ...
2
votes
2answers
75 views
How to 'trace' areas from the layer below?
I have some Ordnance Survey vector data for my local area. I want to create a new layer and on it 'trace' some of the areas, fields, verges etc from the layer below with the intention of then ...
2
votes
2answers
418 views
How to render a multi-layered (raster + vector) map to a file (PDF, SVG or JPEG, PNG)?
When using OpenLayers I can compose a map with several layers which is displayed nicely by my browser, but I need to do the same server side (no browser composing the layers), and I'm waiting a image ...
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!
2
votes
1answer
863 views
Openlayers get coordinates from polygon
please could someone help me and bless me with an example of how to get coordinates from a polygon in OpenLayers?
2
votes
1answer
84 views
How to calculate the percentage of a Line through Polygons?
I have a straight line which runs through a bunch of polygons, which don't have spacing between them (border to border).
Is there an easy way with QGIS to calculate which polygons it passes and by ...
2
votes
1answer
178 views
How to get all Vector layers from OpenLayers map?
OpenLayers.Map object exposes a method call getLayersByClass. How do I use this method to retrieve all of the Vector layers from the map?
I tried map.getLayersByClass("Vector") but this returned an ...
2
votes
2answers
367 views
Measuring the distance between lines and points in QGIS
Using QGIS - I have a vector of fault lines. I have point data in the form of a csv which I have also loaded into QGIS. I need to know how far each point is from the nearest fault line then enter ...
2
votes
1answer
564 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 ...
2
votes
3answers
1k 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 ...
2
votes
2answers
266 views
How to combine vector layer and wms layer based on some constraints?
I would like to group wms and vector layer together but with some constraints in openlayers. The requirement is, if lets say vector layer 1 is selected then its corresponding wms layer should also be ...
2
votes
2answers
973 views
How to query which features of all vector layers intersect with a given bounds?
I am writing a Openlayers map app, and wondering whether there's a better practice to query which features of which vector layers intersect with a given bounds..
It's certainly not a good idea to ...
2
votes
1answer
312 views
polygon map overlay algorithm
There are many algorithms for binary map overlay operation in vector data format which take two layers of map and produce resultant layer i.e overlaid layer as output.
I am wondering whether there are ...
2
votes
3answers
871 views
Convert Arcgis Rest to OpenLayers Vector
i am working with openlayers and esri rest services... in my api due to esriGeometryPolygon for all city , rendering map is taking lots of time ..there for i dont take a good result.. first of all is ...
2
votes
1answer
63 views
How to close and fill Gulfs and inlets in QGIS or Grass?
I have a raster layer from which I extracted only zones with a certain color, then polygonized it with QGis. I just generalized the new vector layer in GRASS to smooth things a bit.
There are many ...
2
votes
1answer
235 views
LoadingPanel - Waiting for Vector & WFS loading
I have vector layer with WFS protocol. and because I have a huge amount of data, there is a while before features loaded on the map.
So i need to tell user to wait a moment until they load by ...
2
votes
1answer
83 views
Is there anywhere that I can obtain global UV data in either raster or vector format?
I'm looking for some UV data (currently with no spatial or temporal resolutions in mind, but ideally split into UV-A and UV-B) for the whole earth. Can anyone recommend a source for data like this or ...
2
votes
2answers
115 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
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 ...
2
votes
1answer
359 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
1answer
408 views
How to clean vector segment intersect errors in GRASS
I'm using GRASS to process a vector map.
When I export back to .SHP and do a 'Check Geometry Validity' in Quantum GIS it lists several errors of this type...
3,segments 199 and 203 of line 0 ...
2
votes
1answer
51 views
How to stop features to redraw unwillingly in OpenLayers
I have a problem where when editing features from a wfs vector layer. After some changes are made to the geometry, the feature redraws itself and the changes are lost.
Usually the problem occurs more ...
2
votes
1answer
145 views
How to remove a vector QgsVectorLayer from QGis python plugin
I managed to add QgsVectorLayer in QGIS through a python plugin, for example:
vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName())
But how can I remove it?
2
votes
1answer
269 views
How to correctly merge layers with overlapping polygons in QGIS/GRASS?
I have 4 vector shapefile that I would like to join/merge, without worrying about attributes.
Here are the shapefiles.
I would like to do an union and a spatial dissolve, but everytime I do a dissolve ...
2
votes
1answer
72 views
From Raster to Masked and Filtered Polygon Vector
I have a set of rasters (geologic risk) from which I want to extract zones with a specific color, clipping them with a polygon (administrative borders), outputting a shapefile.
I'm using QGis (and ...
2
votes
1answer
255 views
GML and GeoJSON vector layer can not display in Firefox and Chrome
I have following codes. It works perfectly in IE (GML and GeoJSON vector layer was loaded), but not in Firefox and Chrome without any errors noticed. Please help me to fix this problem.
Here is the ...
2
votes
1answer
966 views
How to change an OpenLayers vector layer from automatic to manual get request?
I have a web server that returns a FeatureCollection in JSON. I was getting this using the code below, which works perfectly:
var vectorLayer = new OpenLayers.Layer.Vector('geoJSON', {
...
2
votes
3answers
752 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 ...
2
votes
1answer
362 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 ...
2
votes
2answers
555 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 ...
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. ...
2
votes
2answers
839 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 ...
2
votes
1answer
393 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 ...
2
votes
2answers
789 views
How to subtract Geometry Point Polygons in OpenLayers?
I have two json arrays, one for background polygon and one for other polygon.
And from them, I got two polygon layers.
backgroundLayer = new OpenLayers.Layer.Vector("Background Layer", {styleMap: ...
2
votes
1answer
478 views
geometryType property of Vector Layers in OpenLayers
ORIGINAL:
I have a couple questions that are focused around the geometryType property with vector layers. When you create a vector layer you can set the geometryType property to limit the geometry ...
2
votes
2answers
487 views
How to query data from a vector map (shapefile)?
We want to obtain the specific place of the boundaries of a shapefile. We want to be able to get the points of each polygon corresponding to a specific place in order to use these data in an ...
2
votes
0answers
174 views
popular solution for display both tiles and vector data in android map app
We are planning to build a location based app like google map in android.
We have some experiences in the PC development,that's to say we have a similar javascript api like google map javascript api, ...
2
votes
0answers
66 views
Is there a way to create a catalog of vector layers in ArcGIS?
Is there a way to create a catalog of vector layers in ESRI? We have thousands of tiles of 25cm contour data which we need to individually find and add to maps. It would be so much easier if there was ...
2
votes
0answers
35 views
Is there a tool for automated quality assurance for vector data captured on raster data?
I wonder whether is any tool(or script) in ArcGIS or QGIS which allows to make an automated quality assurance for vector data captured on raster data?
vector data on binary raster:
2
votes
1answer
251 views
How to use a sld file with Openlayers using OSM data?
My app, made with openlayers, displays building data called from overpass api.
var data_url = "http://overpass-api.de/api/interpreter?data=(way[building](bbox);node(w););out body;"; //main working ...
2
votes
0answers
197 views
how to search a vector/wfs layer
I'm using Geoserver/PostGIS/openLayers
I've succesfully set a vector layer. And now I'm trying to create a search functionality.
But something goes wrong.
First I set up the layer and add some basic ...
2
votes
0answers
89 views
How to Create a Vector Field from Separate u and v Data Files?
I am using Quantum GIS and trying to create a vector field using data from two separate netcdfs. One contains the u data, one contains the v data. Can this be done, and if so, how? Thanks.
Jason
2
votes
0answers
66 views
problem with saving to esri file
I was using Wroclaw 1.7/GDAL 1.9(earlier release)/Grass 6.4/GSL 1.15-2 and started getting the following message when saving any item to esri format.
"Export to vector file failed.
Error: creation of ...
2
votes
1answer
85 views
Error when importing vector layer into GRASS
I am trying to import a vector layer into GRASS, but I keep receiving the same error. The values in the vector layer are important because I would like to use them to create a heatmap. What could I ...
2
votes
0answers
95 views
how to align vector and raster images? [closed]
How to align vector and raster images?
For example vector images will be static/rigid and raster image will be morphable. For example I manually do initial guess and algorithm must converge to optimal ...
2
votes
0answers
184 views
Reclassifying a field in vector files in ArcGIS
ArcGIS has a reclassify tool that works with Raster files only.
Is it possible to have the same functionality for a vector file?
On the basis of one of the fields in a feature class, the tool ...
