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

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3 views

OpenLayers 3. Problem with displaying GeoServer WFS layer

I am trying to add polygon wfs layer using JSONP format, but something is wrong here. Console shows no errors and this layer, and by countries.getSourse().getFeatures() I receive just[]in jsonp ...
4
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0answers
19 views

Removing some bands or layers from a tiff using gdal

I have been working on a multiband raster image. It is a pix image. I need to just work on the 26 bands that are raster files and not the 4 bitmaps that are are also included in the pix image. I could ...
2
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1answer
17 views

How to style a Vector layer in QGIS using a numeral of an attribute

I have a simple vector layer in QGIS that I would like to style with numerals based on the ID attribute. For instance, point with ID 1 will show up as the numeral 1. Is this possible with default ...
3
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1answer
20 views

How to clip vector data from raster data?

I have two files: National land cover data (raster) HUC 8 (vector files of watersheds) Both are national scale but the HUC 8 takes up a larger geographic region than the raster set so I want ...
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1answer
18 views

How to calculate raster data in vector area?

I have two layers. One is a layer of USA ecoregions (there are 9 ecoregions). It is not raster (so it's vector?). The other layer is the National Land Use Data set (so I know where there's ...
2
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1answer
20 views

How to make my PostGIS vector layer in QGIS visible?

I have loaded a shp file (simple polygon with one entry) into PostgreSQL 9.3 (with extention PostGIS v2.1.3). I now want to load this layer into QGIS (v2.2.0 Valmeira) via the "load Postgis layer) ...
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1answer
16 views

Why isn't Mapbox viz styled how it is in projects?

When using the Mapbox "Projects" editor, I'm finding the previews do not style the same as the end results on the page. Is anyone experiencing similarly? In Projects, my map looks like on the left. ...
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1answer
28 views

Why doesn't my Mapbox + Leaflet viz look retina-friendly?

This is probably a very simple question but it's not clear to me. The Mapbox docs say: When you create a project from the editor, Retina (high resolution) tiles are automatically used on ...
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36 views

How to merge overlapping and duplicate lines from vector layer to one single line?

I used the "polygone to line" tool from QGis, to get a line-layer from this polygon-layer: unfortunatly this causes overlapping and duplicate lines, after I broke the qgis-export via GRASS into ...
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4 views

how to re'display feature after using my 'filterFeature()' function?

the code below is a function that hides a certain region in the map. the problem is i can't redisplay it, i've tried removing this line wfs2.features[i].style = {visibility:'hidden'}; but it says ...
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1answer
22 views

Split linear features from non-linear in the same feature class

I have a vector layer (Originally a raster layer) of well sites, cut blocks, and seismic lines all lumped together in the same feature class and no distinguishing attribute between them. I want to ...
3
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1answer
29 views

How to change the color of vector layer of QGIS in api?

I'm using QGIS-2.4.0 api to develop app in C++. When I add a vector layer to the app, the vector map's color would be random. I used QgsFeatureRendererV2 to get the geometry type of the layer, my ...
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1answer
27 views

Adding vector layer over WMS using OpenLayers?

I am trying to add vector layer to my map from a GeoJSON file stored in the same directory as my maps index.html. However It wont work. Is there something wrong with my syntax? My code: ...
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0answers
17 views

NVS Vector Stream Order Tool gives 000816 Tool is Not Valid in ArcGIS 10.2 for Desktop? [duplicate]

I am trying to use the NVS vector stream order tool (designed for ArcGIS 10.0) in ArcGIS 10.2. The tool is available for free. Whenever I attempt to operate the tool I am met with the error message: ...
1
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1answer
27 views

QGIS vector layers do not match DEM?

I have a DEM (saved as a .tif) and, using QGIS, I want to clip the DEM using a vector mask. The function will not work. Am I missing critical step?
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1answer
39 views

In OpenLayers 3, how do I draw an extent as a LinearRect?

In OpenLayers 2, this was an easy feat. I was able to simply instantiate a LinearRect given the coordinates of my BoundingBox, and then add the LinearRect as a feature to a vector layer I had added to ...
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0answers
17 views

Zoom to a vector feature in a vector layer

I am using OpenLayers+GeoServer and I have a vector layer in a map with some features I would like to make a zoom and show the map centered in one of these features that I can get by ID. How can I do ...
2
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0answers
22 views

Extracting gridded data from polygon vector layer

So I've spent a few enjoyable (and frustrating) days teaching myself the basics of QGIS and fiddling around to try get some data output I need to drive some calculations. Sadly I'm not having any joy ...
2
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2answers
32 views

Assigning a vector to a field in feature class (UpdateCursor)

I don't know if my mistake is of a general nature. I come from R where it is very easy to store a vector in a matrix column. So now I (new to coding with arcpy) am desperately trying to do the same ...
1
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1answer
39 views

How can I transform raster to vector in ArcGIS?

I want to convert from raster data to vector dataset using ArcGIS. Raster data consists of pixels and center of z values. Vector data sets consist of points, lines and polygons and x,y values. When I ...
4
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3answers
120 views

Can you recycle shp and shx files in a shapefile vector grid where only dbf data changes?

I'm periodically getting data from an external partner that is bound to a very large vector grid in shapefile format. The grid itself sits at around 400~ megabytes, but the only data that ever changes ...
5
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1answer
124 views

Merging and joining two line feature classes while maintaining attributes from both using ArcGIS for Desktop?

I created an event layer using the MAKE ROUTE EVENT LAYER tool based on anticipated scheduled events. The road layer which is the base layer is intact. What I would like to achieve is combine layer ...
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1answer
23 views

3D rubber sheeting using ground control points

I have 3d lines that I would like to rubber sheet or rectify in 3D (including z rectification). I used ogr2ogr with -gcp, however all the vertex of a polyline were set to a single elevation, and since ...
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1answer
23 views

Preserve polygon boundaries when vectorizing a raster according to a polygon vector

I have a raster which I clip by some polygons and then convert to polygon. I would like to obtain the same number of polygons in both my vector files. The problem is that some areas in the vector ...
3
votes
1answer
51 views

Calculating distances from points to the centre of cells

I am using QGIS 1.8.0 (using older version because I need the Qmarxan plugin which is not available for 2.4.0). I have a study area that has a vector laying of "planning units", or cells over the top ...
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0answers
42 views

OpenLayers - Add points at vertices of line while drawing line

I would like to create points while I draw a line on my map in OpenLayers. That is, at each vertices of a line and at the end points there is a shape like a square, circle, or diamond. I have this ...
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0answers
20 views

Openlayers text symbology is not being shown

I have a Vector Layer in a .json file: { "type" : "FeatureCollection", "features": [ { "type": "Feature", "properties": { "Station_Id":107, "NAME":"ARDEBIL(F)","ELEVATION":"1314.3"}, ...
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0answers
35 views

QGIS polygon areas inside a polygon

I'm having hard time doing the following analysis in QGIS: I have watershed polygons with individual IDs. Then I have four different shape files, each having different land use polygons. I would ...
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0answers
35 views

Clipping between features within a single vector?

Is it possible (via the Qgis API and friends), to clip polygonal features within a single vector layer? The hope is to accomplish this without having to duplicate the feature into a new layer. ...
3
votes
2answers
70 views

Merging raster and vector not working

I have 1 vector layer (counties) and 1 raster layer (population density). I have tried merging these two, so that I can examine population density within a county, but I have had no luck. It just ...
1
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1answer
46 views

Is there a PostGIS function to get a tangent and normal line?

I'm looking for a function that will return a tangent (and normal) for a LINESTRING in PostGIS. I think this is the 3rd time I've come across the need for this function and everytime, I end porting ...
2
votes
1answer
73 views

Update Attribute based on spatial location

I want to spatially (Spatial Join) update few fields, not all, from another feature class. Is there any way to select and update few fields instead of all the fields from the other layer and ...
2
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0answers
33 views

Adding feature to GeoServer vector layer using WFS-T in absence of fid index?

I want to add a feature to GeoServer vector layer with WFS-T. When I use saveStrategy.save(), an error returned that said: java.io.IOException: current fid index is null, next must be called ...
1
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0answers
29 views

Create vector layer from feature collection in OpenLayers

I have used a WPS process gs:UnionFeatureCollection to compute the geographical union of two collections of WFS vector features. The process returns a collection of features which I intend to display ...
4
votes
2answers
49 views

How to show labels for all polygons in a layer, even with 'NULL' values?

I have a polygon layer which contain information on property name, number of trees within the polygon, average height, and min- and max height values. My problem is, I want to label each polygon with ...
1
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2answers
44 views

How to show average walking distance to closest point in census tract in ArcMap?

Given a map layer of point locations, and a second map layer of census tract polygons for the same area, how would you create a map layer that shows the average walking distance to the closest point ...
1
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1answer
32 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
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
29 views

OpenLayers - cannot set layer opacity

I have the following problem: by default, you can simply change the opacity of layer by writing for example: layer.setOpacity(0.3); But when I add it to my map SelectFeature controls, my layer is ...
1
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1answer
32 views

Deleting vector lines beyond image extents using QGIS?

I am using QGIS 2.2 I have one vector line layer (roads) that stretches beyond my base image (see below). I wish to have the roads "clipped/trimmed or deleted" right at the edge of the image's ...
2
votes
1answer
67 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 ...
1
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0answers
30 views

Vector layers without geometry in QGIS?

Using QGIS, I have set up a couple of automated layer additions via the toolbar. After adding geometry in each respective layer (point, lineString, polygon) and saving changes to the layers, the added ...
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0answers
15 views

Vector Layer Symbol (ism) properties?

I would like to streamline the render of a polygon grid vector layer as a simple line (no fill) via Python coding. I am I bit confused by the implementation referenced by the API. Is it possible to ...
0
votes
1answer
69 views

How to perform an attribute-weighted sum of multiple polyline features from a single vector layer?

I have a shapefile of ~8000 polyline vector features representing traffic journeys on road routes. Each has an attribute representing volume of traffic for that journey. The routes are all generated ...
1
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1answer
61 views

How to batch-process attribute tables in QGIS (or GRASS)?

I'm using GRASS 6.4.3 in Linuxmint 16. I have a bash script for GRASS which I use to process almost 300 raster files. The script first imports some raster files (r.in.gdal), then does some ...
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0answers
73 views

How to create a rainfall raster from rainfall contours?

I downloaded a free rainfall data from the Philippine GIS Data Clearinghouse (PhilGIS) which are vector lines. How can I extract the data points from this? I want to extract it because i will be ...
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0answers
36 views

Polygonize Missing Polygons

Polygonize is not capturing all of the pixels in an image that has been converted to 0s & 1s. The pics below show -original geotif -geotif recalculated to 0s & 1s -polygonize output As the ...
4
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0answers
45 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data; one set are points measured in the field and the second set is a Lidar data set. I want to check the accuracy of the Lidar in comparison to the measured data. ...
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0answers
42 views

Polygonize only pixel values of 1 from a raster

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
0
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0answers
62 views

How to create a vector layer from a GeoAlchemy2 query?

I'm currently developing a QGIS plugin where I mapped a PostGIS database via GeoAlchemy2. I wrote a function that returns results from a GeoAlchemy query but have no idea how to create a vector ...