A coordinate-based data model that represents geographic features as points, lines, and polygons.

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7
votes
4answers
15k views

Customizing Popups in Openlayers

Is it possible to customize the shape of popups in OpenLayers? For example, I am creating a pop-up using the following approach: var popup = new OpenLayers.Popup.FramedCloud( "popup", ...
8
votes
3answers
4k views

How to create a new Spatialite database in QGIS

I've been trying to create a new spatialite database within QGIS 1.8 (SpatiaLite Version 3.0.1; QSpatialite 6.0.3) and keep getting this error: "The SQL query seems to be invalid. no such table: ...
0
votes
1answer
210 views

QGis : superimpose 2 rasters georeferenced (adjustment)

I am pretty new in QGis and I encounter the following problem. I have 2 rasters, let's say, "cadaster" and "tranchot". The raster "tranchot" was georeferenced from the raster "cadaster" with QGis. ...
9
votes
2answers
2k views

What's the best way to display thousands of polygons in Openlayers?

I am trying to create an Openlayers map that will display thousands of polygons. And when the user clicks on each, I want some of the metadata to display. Working with this large of a dataset seems ...
3
votes
2answers
445 views

How to set the color of a feature depending on attributes with PyQGIS?

I'm trying to set the color of a vectorlayer feature depending on the feature attributes with PyQGIS. How do you acces the attributes of a vectorlayer feature?
2
votes
2answers
1k 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 ...
1
vote
2answers
372 views

How to join polygons and lines vector maps from openstreetmap?

I am struggling with the data format OSM gives me: I want to use OSM data for routing, but all round-abouts and parking lots are not in the lines layer. They are situated in the poly(lines) layer. ...
5
votes
1answer
10k views

OpenLayers, zoom to vector layer extent

It seems quite simple thing to me, but I get an error. map declaration map = new OpenLayers.Map('map_element', {... projection : _projObj.mercator, displayProjection : _projObj.wgs84 } layer ...
6
votes
3answers
2k views

30,000 data points… can this be reasonably served using openlayers?

I'm trying to tackle a web GIS problem and need to figure out the best strategy. I have a map with 30,000 cells on it forming a grid for the province of Alberta. I have a list of data points for ...
1
vote
1answer
1k views

OpenLayers : How to make a marker fixed [duplicate]

Possible Duplicate: How to skip drag event to stop a feature being dragged I've created a map and added markers to baselayer on click by using this code : vectorLayer = new ...
5
votes
0answers
54 views

How are the edges of a polygon defined? [duplicate]

Possible Duplicate: Are long lines in shapefiles to be considered geodesics or straight lines in the 2D latlong space? In various representations, such as shapefiles and kml, polygons are ...
0
votes
1answer
1k 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
2k 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 ...
13
votes
3answers
6k 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 ...
3
votes
1answer
280 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
955 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
490 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
325 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
3k 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
747 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
946 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
2k 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
5k views

Is there any way to extract coordinates of a road segment using 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 coordinates of a road segment ?
1
vote
1answer
66 views

OpenLayers - vector boxes and paths

I'm using OpenLayers to make warehouse map. How to prevent drawing lines (paths) over some vector objects already on the map?
3
votes
4answers
11k 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
712 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
1k 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
530 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
4k 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 ...
5
votes
1answer
7k 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 ...
4
votes
2answers
562 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 ...
14
votes
2answers
423 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
619 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
4k 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
961 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
602 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
279 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
572 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: ...
5
votes
1answer
1k 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
963 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 ...
4
votes
1answer
1k views

Splitting lines at a specified distance

Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
4
votes
1answer
4k views

Change vector projection in Openlayers

I have added vector layer to map: vactorTest = new OpenLayers.Layer.Vector("Editable Features", { strategies: [new OpenLayers.Strategy.BBOX(), saveStrategy], projection: new ...
5
votes
1answer
5k views

Showing menu based on right click on Point Geometry in Javascript

I have implemented a vector layer(using javascript) in open layers which is having point geometry. Now my requirement is to show menu just besides with the point whenever we do right-click on ...
1
vote
2answers
228 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?
2
votes
2answers
3k 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
2k 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
1answer
307 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
181 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 ...
5
votes
2answers
979 views

QGIS affine - form of equation

I am at the mercy of a govt authority who have provided utility information in a cad format with a 0,0 origin and a nonsense grid. About a dozen files, the grid and origin are entirely arbitrary. To ...
2
votes
1answer
133 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. ...