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

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7 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
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1answer
26 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 ...
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14 views

How can I sync a vector image with a leaflet map?

I am trying to create the following: For the user to interact (hover, click, etc) with vector layers on the left, and have a leaflet map respond to it on the right. I have used the following that ...
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0answers
13 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 ...
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28 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... ...
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1answer
62 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 ...
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0answers
10 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 ...
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1answer
23 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 ...
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1answer
34 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 ...
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2answers
49 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){ ...
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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 ...
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1answer
39 views

Make diagonal grid in QGIS, divide square into squares

I have square polygon which is aligned under some degree and I want to divide this square to, for example, 25 smaller squares, which must be under the same degree in this square polygon. How this can ...
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1answer
26 views

Is it possible to not show node in editing mod QGIS

I actually have a plugin that allows me to draw on a vector layer (I made it based on the FreeHand Editing Plugin). When a mouseMoveEvent is detected, it creates a new point on the vector layer and ...
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1answer
39 views

Simultaneous multiple vector layer intersection algorithm

Is there an algorithm, you can suggest or recommend, that I can implement to intersect multiple vector layers? I have a few hundred layers I want to intersect and thinking of developing a little QGIS ...
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0answers
26 views

How to make a model with more than 2 input layers for buffering and merging?

Would it be possible to add more inputs to Buffer and Merge? From what I can see there is a limit of two input layers per both. As far as I know this is possible in ArcGIS's Model Builder but from the ...
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1answer
23 views

Vector Click Event is not working

Actually I figured out some problems and corrected it. I declared the overlay just outside the init function. So now I got the 'featureselected' event working properly. But 'featureunselected' event ...
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1answer
61 views

Land cover modifications in different time periods

I have several shapefiles which contain buildings built in different periods from 1948 to 2013. My question is how could I see which buildings for example in were built 1948 but are missing in later ...
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32 views

OpenLayers vector are not filled

I've a small issue with openlayers vectors. I found an svg marker and I want to change the filling color. I found this example, but it doesn't work with my svg. Here is my example code: <html> ...
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1answer
45 views

Country border between two points

I am trying to extract country borders between two points, using Python. The border is a Shapely Polygon.exterior or LinearRing, the start and end points are Shapely Points. My idea is the following: ...
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1answer
40 views

joining non-spatial pollution model (csv file) to Qgis

I need help..I have csv file with concentration data but without coordinates. Start of pollution concentration connect with that one point on map. Is there any chance ? Start of pollution ...
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2answers
138 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... ...
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1answer
37 views

Is the QGIS “Random selection within subset” selecting spatially random or randomly from the attribute table?

I am trying to figure out exactly what is being randomly selected. I have a layer of road segments and I would like it to select a road segment at random within a neighborhood (the subset). This would ...
2
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1answer
117 views

Sketch event in Openlayers 3 drawing interaction

For drawing Polygon in OpenLayers 2 we could use as follow: function drawEnd(){ ... } function putPoint(){ ... } function sketchModified(){ ... } function cancel(){ ... } var ...
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0answers
7 views

Performance: Reproject Cache vs. Drawing Vector data in correct projection

I have quite a bit of data that I am caching from UTM to Web Mercator. This is fine, but I have another process that automatically creates map book pdfs. These map books have been setup to read the ...
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1answer
21 views

Not all polygons removed when cutting from vector layer in QGIS

I have created ten polygons representing lakes on a vector layer, and I am trying to cut them from an imported and re-projected vector layer of administrative districts. When I use the 'Cut with ...
2
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1answer
38 views

Vector tiles in ArcGIS

I have a vector map (consisting of several polygons) and I would like to create several overlapping tiles. I did the same for a raster map using "split raster". For the vector map, I created an ...
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2answers
43 views

How to deactivate the Color Ramp in QGIS graduated vector styling?

I want to display points with different size and I DO NOT want to have a color ramp. Do you know how I can do that?
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0answers
51 views

How to get a “clean” polygon after using dissolve in QGIS?

I'm trying to obtain the boundaries of shapefile, thus to clean the inside as a matter of speaking. While I had expected that dissolve while get me a proper polygon, unfortunately it still has some ...
2
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1answer
86 views

OpenLayers 3.5.0, clear highlighted feature after removing feature from source

I want the user to be able to delete the highlighted feature. This works well, but the feature is not cleared until I move the pointer outside the feature geometry. I am using the OL 3.5.0 library. ...
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4answers
201 views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
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1answer
78 views

Adding in multiple layers in OpenLayers 3

I am trying to add in the following two layers into my OpenLayers 3 map. The issue i'm having is that whichever one is written in last is the only one that is showing. I imagine there is a way to ...
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0answers
42 views

Splitting lines table using point table in PostGIS

My problem is that I want to get the shortest route between multiple point pairs which are stored in a table (PostGIS). In PostGIS I also have a network created using pgr_createTopology on a table ...
2
votes
1answer
31 views

How to set feature vertex Z from an intersecting feature's Z?

In ArcGIS how can I set the Z values of the portion of a line that intersects another line to the Z values from the other line? A batch process is preferred. I tried FeatureToLine, but the null ...
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0answers
27 views

Extracting area from DEM Raster?

After applying constraints to the DEM I polygonised the raster (using GRASS r.to.vect.area) The result is shown below with a lot of vector with resolution = [30 * 30] Is there any solution to make ...
2
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1answer
76 views

Feature is a point or polygon

Im new to GIS and am just curious if there is an instance where a feature can be a point in one map and a polygon in another map and vice versa?
1
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1answer
63 views

How to use QGIS field calculator between different points of same layer?

I'm in a course learning about GIS systems, and we have recently recorded a gps track. I've exported this track as .gpx and imported the points into QGIS. Each point has a timestamp. One of the ...
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1answer
19 views

Openlayers cluster stragegy total count

How can I get total feature count of vector layer: var mylayer = new OpenLayers.Layer.Vector(null, { "protocol": myWFSProtocol, "styleMap": style, "strategies": [ ...
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1answer
16 views

Make OpenLayers filter initially empty

I have an openlayers vector layer that loads data form service. But it loads all data initially. var mylayer = new OpenLayers.Layer.Vector(null, { "protocol": myWFSProtocol, ...
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0answers
27 views

Snapping to a grid does not work

I have two shapefiles that were created in GME using the generate vector grid. They both have the same projection NAD 83 Transverse Mercator. The grid size is 5000m. The grids overlap in that they ...
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1answer
40 views

Merging SHP lines with attribute data combined?

I have one shapefile which contains hiking routes and another shapefile which has ski routes. Sometimes they follow the exact same path. In QGIS if the lines mentioned above are in the same SHP I ...
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0answers
37 views

3D building data for London

Any tips on where I can find 3D building data for UK/London, preferably LOD2 (Including roof structures)? I am aware of the Virtual London dataset but I would like a more recent one.
1
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2answers
43 views

QGIS modeler - how to extract polygons by multiple arguments?

I'm using QGIS modeler to extract lines by not one, but multiple attributes. For example, I have a road network, and I want to extract only road with character values in field TYPE: value_one and ...
4
votes
1answer
74 views

Which system of units does the unit 'degree' belong to?

Let us say that I would like to store latitudes and longitudes like this: lat 35 degree long 80 degree Which system of units does the unit 'degree' belong to? It is not really a SI unit nor a ...
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0answers
24 views

Selecting polygons using another polygon? [duplicate]

Hi, How is the best way or fastest(if there is) of selecting polygons of a different shapefile using a polygon of another shapefile. exercise example: i want select all the light brown polygons ...
0
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1answer
54 views

Latest shapefiles of Indian states

I need shapefiles of Indian states that of 2011 which has almost 671 districts of India. Can anyone please help me?
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0answers
52 views

Why does the transformation bring bad results?

I have this map which has a polygon drawn on it. For the background map I use a WMS via ol.source.TileWMS and the polygon uses a ol.source.Vector object. Normally my view projection is EPSG:31467 but ...
2
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0answers
53 views

QGIS's “Points in Polygon” counts zero in every census tract

I am mapping the location of incidents of asthma using QGIS. I would like to count how many points are in census tracts to better understand the areas where asthma occurs most frequently. My map ...
4
votes
2answers
116 views

Calculating average raster to point distances within census tracts

I have some experience using ArcGIS, but mostly with the field calculator in the attribute table/spatial joins, so I apologize if I say something that doesn't make sense. To provide a bit of ...
1
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2answers
29 views

Selecting/Exporting points from one layer that do not overlap with the points from another layer in Qgis

I am working with QGIS and have the following problem to solve: I have 2 point layers. Layer 1 has more points than Layer 2 but all points of Layer 2 have the same position as Layer 1. I need to find ...
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1answer
37 views

QGIS: Delete information from rasters and shapes that are out of country borders [duplicate]

I am trying to make topographic maps for some countries and show only those countries. I already created reliefs from SRTM-data and imported lake and river data from Natural Earth. Now I want to ...