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

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1answer
61 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 ...
2
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0answers
77 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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0answers
9 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 that I can't redisplay it. I've tried by removing this line: wfs2.features[i].style = {visibility:'hidden'}; but ...
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1answer
27 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
36 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
49 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
18 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: ...
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1answer
35 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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2answers
136 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
22 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
42 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
40 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 ...
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1answer
47 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
138 views

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

I'm periodically getting data from an external partner that is bound to a very large fishnet (vector grid) in shapefile format. The fishnet itself sits at around 400~ megabytes, but the only data that ...
5
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1answer
175 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
31 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
34 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
70 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
99 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
24 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
37 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
41 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
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2answers
82 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
61 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
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1answer
89 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
53 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 ...
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0answers
69 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
57 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 ...
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2answers
64 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
38 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
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1answer
30 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
38 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 ...
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0answers
16 views

Shift between Open layer and vector layer QGIS 2.20 [duplicate]

Can you please help me solve this issue with Open Layer Plugin. I see some shift with a vector layer of Laos water boundaries when the background is Google Physical Layer.I am using CRS EPSG: 32647 ...
1
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1answer
34 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 ...
3
votes
1answer
125 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
41 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
18 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
95 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 ...
2
votes
0answers
54 views

What C/C++ libraries exist to transform vectors between map projections

Has anybody written a C/C++ library (preferably one that is aware of Proj.4 definition strings) that has a set of routines to convert vector quantities (e.g., wind speed and direction) between map ...
1
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1answer
74 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
90 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
39 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 ...
5
votes
0answers
70 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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votes
0answers
61 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
66 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 ...
2
votes
3answers
426 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 ...
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0answers
34 views

QGIS Rasterization of points

I have a point vector layer and want to make it a raster. Trouble is that many points are very close to each other, so unless I specify a very small resolution of the raster cells, likely several ...
0
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1answer
57 views

Process to georeference corners of vector file?

I am new to QGIS and trying to wrap my arms around it so please bear with me. I have vector files (DXF) that I need to add back in the georeferencing. They were edited with Illustrator so I loose ...
0
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0answers
10 views

Adding (ir?)regular vector points

I run 2.0 qgis. (I am quite the rookie) I would like to add a point layer which is regularly spaced every 5 metres along the x-axis, and regularly spaced every 1m along the y-axis. I cannot seem to ...
0
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0answers
64 views

USA MSA/City/County with SImplest Border in JSON

I deal with a lot of poloygon-related JSON representing US places regularly. One thing that could make reading JSON with my eyeballs easier is having a short list of US places whose borders have ...