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

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0
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2answers
102 views

How to drag a point and then use savestrategy in OpenLayers

Im trying to use the wfs-t in openayers using the savestrategy. I have created a savestrategy and it works when I for example uses the DrawFeature Control to add a point. A new point is added to the ...
0
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0answers
55 views

How to simplify vector lines into an overlaid grid in QGIS?

I'm a relatively new user with GIS software (primarily QGIS) and I'm sure this is probably quite simple but I've been trying to find an answer for ages! I have transportation network data for an area ...
2
votes
2answers
93 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 ...
1
vote
2answers
97 views

How to clear attribute columns from a Shapefile?

I want to clear all columns from a SHP. Only need geometry of features. I use QGIS and Sextante with grass and saga. Is there any tool for this job...
1
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0answers
50 views

Flow direction for line segments

My sanitary sewer data (shapefiles) is being merged with data from another GIS firm for a large project and they are asking me to flip all my line segments because they believe they are backwards but ...
1
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0answers
101 views

Problem using grid with a vector layer

I need to establish a model of maritime pollution and I try to use the grid option to work on ocean sectors. I tried to use my grid on a vector file, .shp, with points. Each point is a maritime ...
0
votes
1answer
151 views

Different Styles Within Vector Layer

Is there any way to configure OpenLayers styling method? I have a vector layer and I would like to style the features depending on a value of a flag variables, so I can't use rules. Lets say I have ...
0
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2answers
319 views

add a vector point on OSM map

I have managed to show Lat and Lon function init() { navigator.geolocation.getCurrentPosition(function(position) { document.getElementById('myloc').innerHTML="Latitude: " + ...
4
votes
1answer
226 views

Raster to vector with gaps in Landsat ETM

I need to find size of water area from a raster (jpg) using QGIS 1.8.0-Lisboa. The raster is a Landsat image with gaps of data in it. I used Polygonize, but the output file shows wrong polygon size ...
1
vote
1answer
49 views

what is the alternative of setZoomLevel in vector based map

It is commonly used to generat map tiles at a certain scale and re-organize them for web map on pc. For example googlem map, and bing map. Then user will use the setZoomLevel(int level) or something ...
5
votes
1answer
1k views

How can I programatically create and add features to a memory layer in QGIS 1.9?

I had a working plugin in QGIS 1.8 which read data from an MSAccess database and added it to a series of memory layers. There is some processing involved in the interim so I don't think simply using ...
1
vote
1answer
783 views

Display list of OpenLayers Features which are currently visible on screen

I have an OpenLayers map a few thousand Points of Interest. These POIs are Vector Features rendered in a Vector Layer. We are loading the POIs once in order to minimize load on the server. Next to ...
3
votes
1answer
127 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 ...
1
vote
0answers
72 views

Base station coverage analysis in QGIS

I want to find base station coverage for a instant location. I have building data. And i determine optimum coverage as 500m far away from a base station (buffer). So how can i find optimum base ...
1
vote
0answers
125 views

Looking for best practice to connect multiple road vector line layers for routing (pgRouting) purposes

The Data I have: Bridges (line layer) Municipal_roads (line layer and does not include information in Bridges) State_roads (line layer that doesn't include Municipal_roads or Bridges) Question: ...
0
votes
1answer
71 views

Give Properties to a shapefile to be used by another person [duplicate]

I have bedrock geoology data. I want to classify the data so it appears with the same propeerties as it does on the suppliers website. Is there a way i can attribute a property to a layer (in this ...
3
votes
1answer
232 views

Visualizing Spatial Query

I'm new to GIS applications and trying to figure out what options I have for visualizing spatial query results that combine raster and vector data using OpenLayers/GeoExt/GeoServer/PostGIS. A ...
4
votes
1answer
94 views

Extract Z information from different vector layers in ArcMap 10.1

I have 2 different vector layers, Layer A detailing the area of different polygons and Layer B having similar size polygons with z values instead. I would need to combine Layer A with Layer B so that ...
0
votes
2answers
167 views

GRASS: populating attribute table with specific values

I have a vector map that includes 100 points. These points were created using v.extract to randomly sample a larger map of 10k points. As such, the 'cat' values range from 1 to more than 10k. What ...
1
vote
1answer
50 views

GRASS: shift point locations in a random direction

I have a vector map that contains 100 points. For each point, I would like to shift it 250 units in a random location. It's easy enough to shift all points in a specified direction using v.edit ...
0
votes
1answer
100 views

Is it possible to update layer source in qgis

I've loaded a few shape files as layers in qgis, and I'd like to make a duplicate of the project and all associated shape files into a single directory. However, all of the layer sources are still ...
3
votes
2answers
684 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.
0
votes
1answer
135 views

render kml 10mb KML file cordinates data on OSM map throws stop running script error in OpenLayer.js file

I am trying to render the kml file having 18000 line string data on OSM map using openlayer HTTP strategy. To render OSM map i am using GeoExt.MapPanel and ExtJS 3.4 viewport. The problem is I am ...
6
votes
1answer
188 views

Assigning costs to a road network : use raster or vector?

I have a road network in a PostGis database (db_routing). In another database (db_environment), I have some spatial features of the surrounding environment (trees as points and water bodies as ...
3
votes
1answer
21k views

What is the difference between Vector and Raster data models? [duplicate]

From: http://support.esri.com/en/knowledgebase/GISDictionary/term/vector%20data%20model vector data model: [data models] A representation of the world using points, lines, and polygons. Vector ...
0
votes
1answer
158 views

Openlayers Linestring over edge of map

im trying to create a route displayer for ships. But im struggling with the edges of the map. When going from ie. 179* to 2* it displays a line across the entire map, instead of displaying it on the ...
1
vote
1answer
119 views

Is it possible to fix a vector layer after I badly georeferenced a map? [duplicate]

Sorry in advance if I missed another question on this topic. I searched for everything I could think of, but I didn't find anything with a solution to my problem. I am quite new to GIS tools and ...
3
votes
1answer
1k views

How do I find vector line bearing in QGIS or GRASS?

How can one extract the bearings from a set of lines in a vector file? I'm trying to find the bearings of several straight vector line segments (simplified contour lines, actually) and can't figure ...
2
votes
0answers
393 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, ...
1
vote
1answer
379 views

How to invert polygons (or other options for exterior styling)?

I have a shapefile containing many polygons that I want to use to mask a raster. I have tried gdalwarp -cutline <shapefile> -crop_to_cutline -srcnodata -9999 -dstnodata -9999 ...
3
votes
2answers
391 views

Overlay Vector Layer on Raster Layer

How can I overlay a Vector Layer on a Raster Layer and assign NoData Values on the Raster where the Vector Layer does not cover the Raster Layer? (preferable with ArcGIS)
7
votes
2answers
187 views

Hashing functions for GIS data

I would like to take geometries from a vector dataset and reduce them to a hash. This hash would then be used to verify the integrity of that data and also identify identical geometries. Do any ...
1
vote
2answers
244 views

How to create Concentric Circles in QGIS?

I'm trying to build a planning tool for center pivot irrigation system. It involves selecting a field (polygon), a center point, and then an outer circle to set the outer limits of the system. From ...
1
vote
1answer
224 views

How to convert a shapefile polygon to raster in C#

Does anybody know a way to convert a polygon (vector) in a shapefile to raster data WITHOUT using ArcGIS Explorer Desktop? Is there a way to do this 'progmatically' in C# (WPF with ArcGIS runtime ...
3
votes
1answer
635 views

Split vector layer by field name

I have a vector layer of 108374 lines I want to split the vector layer into field names of the layer, which is 17. Now, I want to create a new vector layer containing one of the field names e.g. ...
3
votes
2answers
178 views

Creating catalog of vector layers using ArcGIS Platform?

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 ...
4
votes
1answer
291 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
3
votes
0answers
94 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
1answer
641 views

How to get the distances (shortest path) between all pairs of points in the river network?

I have 2 vector shapefiles (one line, one point), and I have tried at least 4 ways to try to get the distance matrix at one time (and most concern the directions of each river segment) quantum ...
1
vote
1answer
169 views

How to reproject this vector layer?

I have a dxf file and use this tool to convert it to shapefile. Then I apply some affine transformations and get a shapefile that does not fit the shapefiles downloaded from osm (EPSG:4326). I know ...
1
vote
1answer
580 views

Drawing pie charts with vectors on OpenLayers?

Is anyone got any examples of drawing pie charts with vectors as markers on OpenLayers ? Cheers,
10
votes
5answers
4k views

Libraries to render vector-based maps in the browser

Is there a open source JavaScript library like leaflet or openlayer which can be used in a web or mobile application and loads vector-based maps instead of images? I only need the road information and ...
3
votes
2answers
4k views

How to connect OpenLayers to PostGIS data?

I have read in OpenLayers how to load KML, GeoJSON etc. vector files in OpenLayers. But how can I connect to PostGIS data. If not, why should I upload my data to PostGIS then instead of directly ...
0
votes
0answers
75 views

What vector file type yields the greatest detail with the Heat Map plugin?

I'm using .shp files built from .csv files and having quirky results. Perhaps there is a better way to begin. The heat map appears to be accurately describing the data but calculates a huge area in ...
0
votes
0answers
169 views

Display a single country with OpenLayers

Can I display a single country using Openlayers? I'm not trying to restrict zoom levels or . I want only one single country to be displayed. The rest of the world cannot be displayed. My reasearch ...
1
vote
1answer
694 views

Illustrator to QGIS workflow for vectors

I vectorized a map in Illustrator and would like to import it to QGIS now. I know I must use DXF for that purpose but when I convert the DXF to SHP with the QGIS plugin it is not georeferenced which ...
3
votes
1answer
863 views

How to convert shapefile to vector emf?

I want to convert a shapefile to an EMF file. The EMF file must be a vector image, not a raster image. Please suggest to me some good packages or tools. Thanks in advance.
1
vote
0answers
46 views

Spatial adjustment for vector shp files in QGIS [duplicate]

How to do spatial adjustment for vector shp files in QGIS? I have a set of 4 cadastral maps of adjacent locations. I have converted them form DWG to DXF and then to vector shapefiles. They are not ...
4
votes
3answers
3k views

Openlayers remove previously drawn polygon on starting to draw next one

Objective: At any point of time there SHOULD only be zero/one polygon(s) on a vector layer with a polygon control. I need the previous polygon to be removed as soon as user starts drawing the first ...
0
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0answers
28 views

Polygonize Raster to Vector Error [duplicate]

I have a problem when I am trying to Polygonize (Raster To Vector). I have a Corine map with 44 different land uses. I run a query and I save the selected areas with Bands 0 and 1. Now I am trying to ...