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

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0answers
30 views

Identify nodes in GRASS

Apologies if this is a really basic question but I have been unable to sort this out: How do I identify nodes in GRASS? Specifically, I am running a Salesman analysis and get the following error ...
1
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0answers
53 views

How to create contours from an IDW raster

I'm new to QGIS and am trying to create vector contours from this IDW raster. I followed Ujaval Gandhi's "Interpolating Point Data" tutorial step by step but am not getting the same results for step ...
0
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0answers
21 views

Making raster from vector

Have you ever met with nan value in raster? Im making raster in qgis from vector (one point) and all I have got is nan value and black raster.
2
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1answer
23 views

How to create a new empty memory layer with fields scheme from other layer in QGIS?

Being a complete noob with python so far, I got inspired by this answer: http://gis.stackexchange.com/a/155988/8202 to dive into it a bit. When creating features in a new target layer from an ...
0
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1answer
156 views

get and change style property openlayers

i need to change the property of some style after its created, and i need to change it with knowing only the string of the property name. i am getting string like "fillColor" and value like "blue", ...
0
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0answers
18 views

Vector layers don't seem to be exhibited properly [duplicate]

I'm a veterinarian that uses qGIS for making basic outbreaks maps, and am trying to branch out and expand what I'm doing. When I first started using qGIS 3 years (I believe it was 1.7), ago, when I ...
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1answer
1k views

Draw order (zIndex) of OpenLayers polygons and points in the same layer

My question is similar but slightly different from this one: http://stackoverflow.com/questions/5003349/openlayers-vector-features-z-indexing I have an OpenLayers Vector layer which contains polygons ...
1
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1answer
64 views

How to get smooth contours from points or IDW raster in QGIS

Hello I'm an artist trying different ways of drawing contours in QGIS using points with income values. I've been able to import a shp file with the data, create a layer with centroids of the census ...
2
votes
1answer
1k views

How to deactivate Vector Selection In OpenLayers wms features

This is my sample code and work fine :), But I have a little problem, I'm using multiple layers (WMS), when I zoom the layer will be shown or hidden. In my example bellow when OpenLayers level zoom ...
2
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0answers
24 views

Creating a 3D model of airspace that I can interrogate to see if some other feature (like a tree) will intrude into the airspace

The goal is to create a 3D model of imaginary planes in space that I can interrogate to see where other objects in the vicinity of the model cut through any part of that plane. For example, an ...
4
votes
3answers
178 views

3d vector and geometry operations in open-source GIS

There is some really good open-source software available to work with 2D vectors. For example QGIS has operations like buffer / clip / dissolve / select by location / join attributes by location... ...
2
votes
1answer
79 views

How to plot certain values of a column in R?

Lets say we have a shapefile of cities with a column called category cities@data category A B A C A A B C How can i plot the A category only etc? Tried c<-cities$category[A] ...
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0answers
24 views

How to run Mapbox Vector Tile Mini Server?

I am trying to make an offline map for the vector tiles that I've exported from Mapbox Studio (mbtiles). I found this : https://github.com/BergWerkGIS/mini-server I have it downloaded on my ...
0
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2answers
33 views

How to measure the sum of the areas of each class in QGIS?

The project has a layer with several groups of polygons with different weights. Each group is associated to a weight. How can I get the sum of the area of each group?
4
votes
1answer
4k views

Change vector projection in Openlayers

I have added vector layer to map: vactorTest = new OpenLayers.Layer.Vector("Editable Features", { strategies: [new OpenLayers.Strategy.BBOX(), saveStrategy], projection: new ...
0
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1answer
233 views

Geomedia WebMap WFS to vector marker layer in Openlayers

Looking for minimal example/advice on getting a WFS service to show up as a vector layer with markers/icons in Openlayers map. I have created the WFS service in Geomedia WebMap 6.01.11.19 and the ...
3
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1answer
27 views

QGIS Convert bathymetry shapefile from fillable to strokeable

In Java I would like to stroke the bathymetry depth lines instead of filling the area. I'm starting with the Natural Earth Bathymetric Data: ...
1
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2answers
1k views

OpenLayers vector does not draw (or re-draw) on zoom level change or layerswitcher off/on

Here is the full code (i'll highlight the important parts after): jQuery(document).ready(function($) { // ...
1
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2answers
64 views

Add overlapping polygons

I have a feature class that contain many overlapping polygons. Each polygon has a field value which I would like to add together wherever the polygons overlap. There are about 100 polygons each with ...
12
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6answers
5k views

Converting GeoPDF to vector format like CAD or shapefile?

I want to convert a GeoPDF that has vectors entity in it to a vector format and preserve the real coordinates of these vectors. The GeoPDF has been exported from ArcMap and has layers in it. I have ...
1
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0answers
28 views

How to convert GeoPDF to ArcGIS with annotations (arcmap original labels)?

I've got a GeoPDF file that contains vector and annotation data (arcmap labels). I need to convert it into a feature class. I've tried to follow the former questions that been asked here: Adding ...
2
votes
1answer
27 views

Multiple display of vector layer in a qgis plugin interface

def initGui(self): """Create the menu entries and toolbar icons inside the QGIS GUI.""" icon_path = ':/plugins/cropEt/icon.png' self.add_action( icon_path, ...
1
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1answer
22 views

Clip & save layer using OpenLayers 2

I ma currently developing a web mapping app. How do I make it possible for my app to clip and save area of interests or area I am working on. I can create a vector layer, modify it and delete if I ...
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0answers
41 views

Turning “normal” Vector Data into a GIS

I have a map in Adobe Illustrator with several vector layers. ( Therefore the vector data have no spatial reference and no attributes. What is the best way to turn these vector data into a GIS and ...
2
votes
1answer
36 views

how can I get the majority (dominant) class of a raster to an area (polygon) using qgis?

I have a vector layer with many basic units of planning (zones), a raster layer with three classes of geology and other raster layer of geomorphology with five classes. How can I update the ...
2
votes
2answers
107 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 ...
4
votes
1answer
411 views

OpenLayers Google v3 and other layers drift apart

I'm stuck. My code works with OSM, but I need it to work with Google as well. The problem is simply that Google v3 and my other layers are not playing well together at all. They don't zoom together. ...
0
votes
1answer
33 views

How to plot a shapefile with colors according to a column numbers in R?

reclass = function(x){ ifelse(x == 0, 10, ifelse(x > 0 & x <= 20, 0, NA)) } arch$ranks<-as.factor(unlist(lapply(arch$ranks,reclass)) arch.col = topo.colors(nlevels(arch$ranks)) ...
0
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0answers
20 views

Problem with passing ranks to different buffers

This issue is really troublesome.i have a SpatialPointsDataFrame which refers to a city.I needed to perform a join with a dbf in order to attach the population column which i did thanks to a couple of ...
2
votes
1answer
55 views

How to join a dataframe with a dbf via a common column in R?

I have a SpatialPointsDataFrame with the data of a city and i want to join it with a dbf that contains the population via a common column that they have. How do i do that so the first one has the ...
6
votes
1answer
6k views

Openlayers wfs vector layer

I'm trying to add a vector layer with a wfs layer and it's not working.Can anyone point a solution? Openlayers code: var wfs = new OpenLayers.Layer.Vector( "Stavros Features", ...
0
votes
0answers
37 views

Converting a (WAsP) vector map to a raster map with GRASS GIS

i'm quite new to GIS and i need to convert roughness data which is available in a vector format to a raster format. The final data should be on a simple 2-dimensional uniform grid with a constant grid ...
1
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1answer
34 views

gdal_polygonize with World File

I have this image that I want to convert it to GeoJSON. And I have this World File: 0.0388048118 0.0 0.0 -0.0387897595 697054.11331 4458020.56656 When I try to run the gdal_polygonize command ...
-7
votes
3answers
1k views

Delivering map tiles in real-time without caching? [closed]

Is it possible to deliver map tiles quickly over the web without worrying about caching or seeding them? With raster map engines this is a problem because endering raster tiles is resource consuming. ...
1
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0answers
24 views

How to create displacement vectors in QGIS using GPS points with different dates?

Is there a way to calculate and visualize displacement vectors in QGIS ? I have DGPS points taken at the same place (ground control points), but their position moved over time as they are located on a ...
2
votes
1answer
327 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 ...
7
votes
2answers
414 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 ...
0
votes
0answers
34 views

Showing/displaying relationship between Earthquakes and Fracking operations?

I am presently analysing the relationship between hydraulic fracture operations and possible associated induced seismicity. I have both the earthquake data (as a shapefile with lat, long, magnitude ...
1
vote
1answer
174 views

Overlapping polygons in the same layer

I am working in QGIS on a vector layer where areas are classified using an attribute "typo". The problem I'm encountering is that many polygons are duplicated or overlapping, with the result that some ...
0
votes
1answer
22 views

ArcMap 3D profile graph gives a level line

ArcMap's Profile Graph in 3D analyst works great for drawing a line on the map and seeing the profile. I am doing this part easily; single segments, multiple segments it works fine. However, it is ...
1
vote
1answer
126 views

Add feature manually to a vector layer in ol3

I'm trying to add a layer manually to a vector layer with javascript. I can't seem to determine why this is failing: http://jsfiddle.net/Kieveli/f4t6n6v1/4/ I've tried sane coordinates like 16,22, ...
1
vote
1answer
57 views

Automatically changing the angle of a symbol in QGIS?

I am working with an iron age cemetery in QGIS. I marked every grave in a point layer with several columns; amongst others, burial rite (inhumation, cremation etc.). I inserted a second column for the ...
1
vote
1answer
43 views

How to measure the distance between multiple points and multiple polygons?

I'm trying to find a quick and accuarate way to measure the distance between 3 survey sites and all the designated sites within 10km. The survey sites are on a point vector layer and the designated ...
1
vote
0answers
31 views

PyQgis - Adding attributes to a POSTGIS layer

After reading @underdark's answer to this question on creating a new vector layer and @Matthias Kuhn's to this one on field calculation, I wrote a script that allows me to calcultate the mean ...
0
votes
0answers
37 views

NDVI from raster to vector isnt working

I have question...can I make from raster img. vector file via qgis? Because Ive tried it on NDVI image and Ive only got one file with atribut table full of #null. Image is from landsat7... ...
1
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1answer
80 views

ArcGIS, How do I get smoother contours?

I am trying to get nice smooth contours using ArcGIS. I have already smoothed out the DEM using focal statistics, simplified and smoothed the contours. The current result looks like this, which is way ...
1
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0answers
15 views

Plugin SWAP vector direction doesn't work in QGIS

I've installed plugin Swap vector direction in QGIS. But it doesn't work. I click and nothing. I need to flip lines (22 000 000 lines). In ArcGIS takes many hours and still flipping. I thought ...
1
vote
1answer
26 views

Render or display only the boundary of a vector layer containing thousands of polygons

This might be a very basic question but my lack of experience makes it really hard to answer. To have a cleaner map to print I want to display only the boundary of a layer composed of more than ...
1
vote
1answer
38 views

QGIS - some edit feature options disabled in vector layer [closed]

I created a new vector layer in QGIS, saving as I went along and then I saved the project and logged out. When I went back into the project, I wanted to add some more features to the same layer, so ...
1
vote
2answers
61 views

Configure default styles in LeafletJS

I want to change the default styles for vector layers in my Leaflet version 0.7.3. I can't find anything about that in in the documentation, so I made this hack: map.on('layeradd', function(e){ ...