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

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3
votes
0answers
375 views

GDAL polygonize lines

I have a raster file containing roads (left image). I polygonize the raster file with GDAL (see the script below). In the end I like to have vector lines. However GDAL only gives me something like ...
3
votes
0answers
132 views

Cross-browser marker animation in OpenLayers

Currently I'm trying to implement animated markers in OpenLayers. I'm using PNGs for the markers, set by the externalGraphic style property on an OpenLayers.Layer.Vector. I need to be able to make ...
3
votes
1answer
130 views

Are there plans for improving performance of vector files in QGIS? [closed]

Does anybody know if there are any improvements planned pertaining to the performance of vector files in QGIS? Right now, a 1 GB file with contour lines needs several minutes to open. In addition to ...
3
votes
0answers
96 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:
3
votes
0answers
426 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 ...
3
votes
0answers
146 views

Is there a way to create raster by interpolating point values using GeoTools 8.2?

im new in using GeoTools (8.2). I was able to create shp from asc file which contains my data. Now my question is is there a simple way to create (interpolate) a simple shapefile (only points) to ...
3
votes
2answers
431 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 ...
3
votes
0answers
943 views

How to get turn angle, line orientation and line length in ArcMap 9.3.1?

I am mapping and analysing animal movements using arcgis 9.3.1 along with Hawthorne Beyer's GME, and am trying to utilise the correlated random walk commands, but in order to do this I need to find ...
2
votes
5answers
2k 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 ?
2
votes
3answers
134 views

Creating a Slope Map Using Contours

I am trying to create a slope map. I have many contour elevation files. I tried to use the slope tool in Arctoolbox, but it calls for raster files and I'm working with vector data. Any help with this ...
2
votes
1answer
434 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")); ...
2
votes
3answers
859 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
229 views

How to calculate mean coordinates from big point datasets?

I know there are several questions related to speed issues in QGIS, but I am having problems when running Ftools. I have a vector with ~70,000 points in it. When I run the generate mean coordinates ...
2
votes
2answers
509 views

Styling OS Vectormap Local in QGIS?

I am attempting to style Ordnance Survey Vectormap Local on QGIS 1.8.0 by using the styling sheets suplied by Ordnance Survey. The styling sheets are available from the OS website ...
2
votes
1answer
3k 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
4answers
83 views

How to set a minimum point snap distance?

There are two points: A and B. I need to snap any points within a 65 m search radius (blue buffer) of point A. However, the snap distance of B needs to be exactly 5m apart from A (i.e. located ...
2
votes
1answer
109 views

graduated labels in QGIS

I've searched on Google but haven't found an answer. The QGIS Dufour GIS provide an enhanced vector-styling interface but is it also possible to graduate the labels like it is possible for the ...
2
votes
3answers
220 views

Ordnance Survey 1 km Grid

I am wanting to get a copy of the OS 1km Grid layer. I have found these previous questions: Ordnance Survey grids - download or generate? and Ordnance Survey Grids But neither provide the ...
2
votes
1answer
103 views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
2
votes
1answer
145 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
81 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
726 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
1answer
1k 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
2answers
301 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
58 views

Comparison of vector file formats

Does anyone know of a chart or table that would explain the benefits / shortcomings of the different vector file formats, eg. .shp, .gml, .kml, .gdb. It seems that ESRI shape is still quite prolific, ...
2
votes
1answer
32 views

unable to draw polygon without attribute window popping up?

I'm fairly new to QGIS and an trying to draw a polygon via "Adding Feature". When I make the first left click to start, the attribute window pops up instead of letting me continue on with additional ...
2
votes
1answer
71 views

Why do layers appear in the wrong order in QGIS 2.2?

I have a problem with in which order my vector and raster layers appear in QGIS. I have raster that I want to be the background of my other layers (vector). I place the vector layers on top in the ...
2
votes
1answer
2k views

OpenLayers Vector Layers: adding and removing features VS. redraw/refresh

I am currently using addFeatures and removeAllFeatures in my code to get the desired results and this is working OK. However, I have been asked to ensure that the vector layers are not being ...
2
votes
1answer
71 views

Is it possible to display two categorical symbolizes for two different attributes in one layer alongside each other in ArcMAP 10.1?

I have a road layer that I would like to display attribute_1 = "speed" on top of the line segment and attribute_2 = "traffic_volume" below the line segment. For each attribute I would like to setup ...
2
votes
2answers
95 views

How to overcome the layer limit on OSX?

I am trying to add many layers to a project in QGIS. After adding approximately 80 layers, QGIS returns this error: "not a valid or recognized data source". There is nothing wrong with the shapefiles ...
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
3answers
2k 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
2answers
409 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
2k 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
417 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
1k 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
29 views

Extract all raster cells outside a polygon

How does one perform the very simple task of extracting all raster cell values outside a polygon? I've been looking through QGIS for hours with no solution to this simple problem.
2
votes
1answer
251 views

Possible workflows for shaded relief representation as vector

I am looking for a good workflow on how to represent relief on a map as vector (e.g. for further processing in Adobe Illustrator or Inkscape). My inspiration is the present google maps at zoom level ...
2
votes
1answer
124 views

How to delete points which are close to each other?

I have a vector file containing thousands of points. Where points are within x distance from each other, I wish to delete one of the points and keep the other (either by snapping to one point, or ...
2
votes
2answers
72 views

cutting and extending one polygon layer in function to the other layer boundaries

I'd like a methodology that can edit my vector layer, extending and cutting the features in the polygon layer "cap_agricola" within the boundary layer "sp_edr", I would like to solve this problem in ...
2
votes
1answer
1k views

How to get attributes of overlaying polygon layers by a spatial query?

I am new to QGIS and would like to merge selected data/attributes out of the attribute tables from overlaying vector objects on different vector layers without creating new additional layers. Is ...
2
votes
1answer
111 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
718 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
135 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
179 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
554 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
626 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
42 views

Memory Vector Layer Corrupted?

I was working with a large data set that had data for roads, rivers, railways, etc. all together so I decided to break the different data out so I could label it differently on the map and check each ...
2
votes
2answers
67 views

Converted GPX file has null values in open attributes

I'm an absolute newbie but I think I'm doing this right. I've got a bunch of .fit files from my garmin. I can use GPSBabel to manually convert these to GPX XML and the map looks fine after the ...
2
votes
2answers
86 views

How can I get repeated vector grid in horizontal direction?

I need to get repeated vector grid layer in horizontally direction. I created many polygon vector grid layers, and their extents as listed bellow (Xmin-Ymin, Xmax-Ymax): Layer 1: 5910000 3040000 ...