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

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3
votes
1answer
795 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
1answer
130 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 ...
3
votes
2answers
348 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
77 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
0answers
437 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 ...
1
vote
1answer
185 views

Vector title attribute can't display?

var vectormap = new OpenLayers.Layer.Vector('Overlay', { styleMap: new OpenLayers.StyleMap( { "default": new OpenLayers.Style({ ...
4
votes
1answer
78 views

Reduce number of vector field arrows in qgis

OK, now that I have figured out how to get my vector fields in qgis, I can't figure out how to reduce the number of vector arrows on the map. Is there a setting for how many vectors are sampled? ...
1
vote
1answer
159 views

How do I create rendered vector field in qgis

Perhaps I am misunderstanding the "vector field renderer" and "VectFieldCalc" plugins, but I have no idea how to make a vector field of arrows, with directions and magnitude. I have the data loaded ...
1
vote
1answer
106 views

Set certain amount of pixels to 1 inside of a polygon (GRASS)

I have a rather coarse vector map with polygons and want to calculate a (sufficiently) finer raster map defined by spatial extension and resolution. Every polygon of the vector map has a value ...
4
votes
3answers
219 views

How to subset X number of features from Shape file in QGIS

I'm looking for a means to take a rather large Shape file and split it out into separate, smaller shapefiles based on number of features. So for example, if I have a file with 1 million features, ...
2
votes
0answers
148 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
5
votes
1answer
391 views

Converting polygon values to a vector grid using PostGIS

What is the best way of converting a value from irregularly shaped poylgons to a polygon grid using PostGIS? I have a set of polygons that look like this: and I would like to overlay a grid on ...
5
votes
1answer
134 views

GDAL/OGR Determine if dataset is raster or vector

I am writing a script using the GDAL/OGR Python bindings and it is possible that the user may provide a raster dataset or a vector dataset as input. If the user provides a vector dataset, the script ...
3
votes
1answer
122 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 ...
6
votes
0answers
227 views

Moving points onto lines (~neighborhood)

I do have two vector layer, of which one is a point layer based on "events" by remote sensing and the second one is a line layer from local research. In my case these are earthquakes and tectonic ...
2
votes
0answers
252 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
2answers
140 views

restrict quantity of features displayed with OpenLayers

I have 14000 point vector features in the map. Displaying them all is very slow (renders at like 1 fps in chrome). How can I tell Openlayers to only display a subset of them, for example features ...
2
votes
1answer
120 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 ...
4
votes
1answer
544 views

Distance Matrix tool in QGIS. How to get result in metric? [closed]

I'm trying to calculate the distance between points in layer with distance matrix tool. And keep getting strange results no matter what. Like this MASTER ------------SLAVE ---------------- DISTANCE ...
1
vote
0answers
226 views

How to update polygon field with point count for multiple rows? (Temporal point-in-polygon)

I have a shapefile with several regions. It contains basic info like ID, Code, Name1, Name2, etc. It is overlaid with a shapefile of points (nearly 200k). Each point represents an event with a type ...
1
vote
1answer
337 views

Intersection between two SpatialPolygonsDataFrame using gIntersection function in R

I want to select a subset of my map (a SpatialPolygonsDataFrame) to create a new vector map = part of the initial map included inside a given polygon (eventually, inside several polygons). I have a ...
5
votes
1answer
143 views

Grid Analysis from samples data

I'm trying to analyze set of samples into vector grids in order to generate average data in corresponding grid.I'm working with 50m separated grids but the size of grid may change over time.That's why ...
2
votes
0answers
150 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 ...
6
votes
1answer
178 views

Fast data representation on the vector layers

I have found an interesting article about how HTML5 supports representation on large datasets. Article can be found here. In the article it is said that HTML5 and feature simplification can ...
4
votes
2answers
1k views

OpenLayers - Get features inside a polygon

In my OpenLayers map I allow users to draw an ad-hoc polygon vector. Then I need to get all the features from a WFS vector layer that fall within the ad-hoc polygon. Here is the code I have that ...
3
votes
1answer
137 views

Creating a vector based design from a raster database

I have a raster table that I've created using Postgis raster. It has 365 records and the table looks like this: +-----+------------+---------+------------+ | rid | rast |filename |date_of data| ...
1
vote
0answers
132 views

How to config geoserver to read style of vector layer from postgis/SQL store?

I've imported vector layers from map info pro to both SQL server and post gis using easy loader. In both cases I've included style column in the exported table. When I create new store in geoserver ...
1
vote
1answer
876 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 ...
5
votes
1answer
492 views

How to emulate a specific vector grid in QGIS?

I would like to analyze data included in a pdf file. The file contains information on characteristics of 16km grid cells for a specific study area. The file also includes a map displaying the grid. I ...
3
votes
2answers
323 views

How to export 2d vector graphic from Arcscene?

I need to know how to export 2d vector graphic from ArcScene so I can edit it with illustrator. I've tried changing the options when I export 2D scene as AI file or PDF file, but they always remain as ...
3
votes
3answers
523 views

DXF to georeferenced SHP

I know how to set projection and georeference bounds of scanned TIFF file, by using gdal, but I don't know how to do the same for vector file. For example I georeferenced TIFF file by using this ...
1
vote
0answers
53 views

SQL server 08 Limitations

The Soil SURvey GeOgraphic (SSURGO) database is a set of very large and complicated shapefiles. We want to load all of the shapefiles for the US into a national SQL database. Are there import ...
2
votes
1answer
481 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
559 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
102 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 ...
1
vote
0answers
58 views

calibrating vector line in qgis

I have loaded GPS points into a QGIS vector layer. I also imported a vector line from a dxf file which doesn't have georeferencing. I would like to fit in line geometry between the GPS points - how ...
2
votes
1answer
101 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 ...
6
votes
1answer
295 views

Why do vectors disappears when zooming in?

I have imported a .gpx file into qgis and separated the track waypoints using Vector > GPS > GPS tools. When viewing at full extent I can see the original track and component waypoints. However when ...
5
votes
2answers
179 views

How to download Leaflet vectors in GPX format?

I would like to use the leaflet.draw plugin to allow users to digitize vectors on the map. At the end the data should be downloadable as a GPX-file. Is there any sample that shows how this can be ...
3
votes
0answers
123 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 ...
1
vote
0answers
23 views

How do I draw a square on a vector layer from PostGIS? [duplicate]

Possible Duplicate: Is there a tool/plugin/script for QGIS that would allow for manual corrections to vectors and also allows for connection to postGIS? I am trying to draw two squares on a ...
3
votes
3answers
183 views

How can I draw squares in PostGIS layers at different angles?

I am trying to draw two squares on a 45-degree angle and then merge them using PostGIS to edit. QGIS can draw squares but only on a perpendicular plane (eg, 0, 90, 180), and I need to be able to draw ...
4
votes
2answers
540 views

Spatial query of raster data

I have population distribution data as a raster layer and exposure contours as vector (polygon) layers. What I'd like to do is use the vector layer to estimate the population indicated from the raster ...
5
votes
1answer
184 views

How to cache PostGIS views?

Does anyone knows if there exists a caching system for views or queries in postgis? I have a system that gives information through a webpage using a postgis view as backend. The problem is that, ...
2
votes
1answer
399 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 ...
3
votes
1answer
1k 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 ...
7
votes
2answers
221 views

How to remove long linear strips from polygons?

I have a polygon layer representing impervious land cover. This was taken from a land cover raster dataset. The impervious data represents all impervious surface that is not buildings or roads. I ...
8
votes
3answers
7k views

Extract Raster Value into Polygon Attribute

I have Raster Data for a State which has Elevation Data in its pixels. I also have Vector layer which has the 300 divisions of State. what I need is, I want to get the average elevation value of ...
5
votes
3answers
854 views

How to update feature positions with clustering in OpenLayers?

I have an OpenLayers 2.12 map with a vector layer with a cluster strategy. All the static behavior is how I want it. Now I'd like to add the possibility to update the features' position. I do this ...
0
votes
1answer
199 views

Vector data(point) is drawn in wrong place on map (OpenLayers)

I need to show a map (world map, used default OpenLayers WMS) and one point on it (with events like onhover, etc). Here is my code: var options = { ...