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

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2
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1answer
62 views

PyQGIS: Change attribute value doesn't work, results in NULL

I am writing a QGIS plugin, which at one point attempts to change several attribute values on a layer. However, in the end no changes are made. If I punch similar code into the built-in Python ...
1
vote
0answers
16 views

How do I generate a sampling path by numbering points?

I need to number points from left to right and then the next row of points the numbering must continue from right to left, then again from left to right the row thereafter - and so on, and so on. ...
2
votes
0answers
36 views

Combining adjacent shapefiles and merging neighbor polygons currently divided by quad boundaries

The project I'm working on has been mapping ecological sites in ArcGIS on a quad-by-quad basis for the past 10 years. When entered into GIS, each quad has its own shapefile and the sites are cut off ...
3
votes
4answers
3k views

Scriptable way to merge polylines that join in ArcGIS

I have a number of polylines (around 9000), a number of which have one or both ends touching another polyline. I would like to merge these ones together into one polyline - thus reducing the number of ...
3
votes
2answers
198 views

QGIS Real-Time Vector Layer Creation

QGIS is running on my Windows PC. I have a CSV file on my PC that is remotely updated with values of a raspberry pi's GPS position and some wifi-status readings. Is it possible to create a vector ...
2
votes
1answer
38 views

Error when trying to subset a vector to a dataframe

I'm not sure if I've used the correct terminology in my title, so please forgive me if that doesn't entirely make sense. For the sake of reproducing my example, I've created a dummy example. As ...
6
votes
3answers
89 views

Select all polygons that are completely within a circular buffer

I made several buffers around some points. Now I want to select all polygons that are completely within this buffer. My problem is that I also get the polygons that are partially outside of the ...
4
votes
0answers
60 views

Buffer neighbouring polygons without overlap using QGIS

Is it possible to create a buffer around neighbouring polygons, so that the new polygons do not overlap? Preferably in QGIS but any other tool will do. So instead of the first result I would like ...
1
vote
2answers
77 views

Vector to raster conversion [solved]

I'm using GRASS but, in case, I'm also familiar with R and QGIS. I'm trying to convert a vector area map into a raster one. My problem is that the resolution of the raster is too low (and I can't ...
2
votes
0answers
32 views

Create polygon layer from point data with number attribute where polygon encloses n% of point data attribute value in QGIS [closed]

I have two sets of data, one is the CodePoint Open with the location of all of the uk postcodes, the second is from online form data from which I've extracted the postcode and telephone area code, and ...
4
votes
2answers
979 views

Calculating spacing of polylines along transects using ArcPy?

I have a shapefile with a number of roughly parallel lines in it, and I want to calculate the spacing between these lines using a number of transects across the map. How should I go about this? I ...
0
votes
0answers
22 views

Is there a way you can see the spatial query that vector uses?

I am using geoprocessing-tools --> intersections to calculate which points are within my circular buffer. It works fine but I want to know what query(/code) vector is using so I can add some ...
0
votes
1answer
38 views

Determining of vector dataset single files to specify its size on a disk

I wonder how to get size of disk space that a specific vector dataset occupies on a disk. I didn't find any ogr2ogr util or OGR Python method that can return a list of files that belongs to given ...
13
votes
3answers
7k views

How to find and merge duplicate points?

I have two point shapefiles: Red and Blue. Each point shapefile has a z value which represents a radius (i.e. represented as buffers in the example). A duplicate point is defined as a point that ...
5
votes
2answers
5k views

Reclass for vector data in ArcGIS Desktop?

I've got a vector dataset (in fact, OS MasterMap data) and I want to set the value of a certain field based on the value of another field. For example: Field1 Field2 Building 20 Grass ...
0
votes
2answers
57 views

how to draw coordinates along the lanes using MultiLineString instead of LineString

I trying to draw lines along the path of the lanes on the map using openlayer3 but i am not getting any lines on the lanes there is no error in the developers console as well <!DOCTYPE html> ...
39
votes
5answers
13k views

Self-hosting Mapbox vector tiles

As presented in a talk at FOSS4G Mapbox Studio allows to create Mapbox vector tiles and export them as a .mbtiles file. The mapbox-gl.js library can be used to dynamically style and render Mapbox ...
0
votes
0answers
234 views

PyQgis: How can I preserve order or index when adding features to a Vector Layer from a file?

As I read data from a text file and add points to a QgsVectorLayer (as well as related attributes), each new record gets 'stacked' on top of the previous one in the Attribute Table (and within the ...
1
vote
0answers
32 views

Using arcpy to add several rasters

I need to do some raster/vector processing on some non-overlapping tiles. My python script needs to find the correct tiles and then extract the raster values and count them up. My script needs to be ...
3
votes
1answer
101 views

How to ‘invert’ or ‘reverse’ a vector cutline when gdalwarp'ing a raster?

I have a raster of North America and I'd like to remove the larger lakes from it, replacing them with the same no-data value as the original raster. So I downloaded Natural Earth's 10 meter lakes ...
0
votes
0answers
21 views

GRASS: strange classification output and reject map from “i.maxlik”

I am trying to perform a supervised classification with "i.maxlik". I have three bands: 1) elevation (a dem); 2) reflectance (derived from Landsat ETM+ band4); 3) cumulative solar radiation (derived ...
18
votes
1answer
298 views

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS?

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS? I have a vector region in GRASS. And I would like to generate a vector (a polyline) being the bostrophedon ...
2
votes
1answer
48 views

Error while executing v.rast.stats command in grass plugin in qgis

I have a vector polygon which I imported in grass. I also have a raster from which I have to extract the value. I ran v.rast.stats command in QGIS 2.12. The command was executed with error. The error ...
1
vote
1answer
200 views

Calculating coverage of vector polygon over other polygons?

I have a shapefile file that contains a LiDAR footprint and I'm trying to figure out how much a county is covered by the LiDAR footprint. Two separate shapefiles. The attribute table for the county ...
0
votes
1answer
37 views

Intersect elevation interpolated from CAD file in ArcGIS

I have two datasets - contours and vector (water, roads,...) Vector layers were used as breaklines to generate the contours. Then the contours were generalized a bit. For quality check I need to ...
2
votes
0answers
64 views

Error trying to save vectorfile in QGIS 2.10?

I'm trying to save some changes I made in a vector file (polygons) in QGIS 2.10. The file contains properties and I want to merge two of them into one. I toggled and selected the two and then pressed ...
2
votes
0answers
519 views

How Can i create a Vector layer from selected features qgis

In my qgis plugin i select dynamically features from a Vector layer. and currently i create a new layer from selection on combining all feature into a new feature: theField = QgsField self.theString ...
3
votes
1answer
337 views

D3 missing zoom Choropleth + Raster

Following this example and Choropleth from Mike's site I am trying to get: image + vector + choropleth = my map As you can see I lost the zoom capability on the vector layer. I have been trying ...
10
votes
2answers
715 views

How do I describe a special relationship between connected edges?

Consider this simple situation where three edges connect at a node: I’d like to write a succinct and clear description of the relationship between A and B in such a way that differentiates it from ...
3
votes
1answer
117 views

Why can't I clip my Shapefile?

I've tried all of these solutions (How to clip a line layer based on polygons with QGIS?) and still cant clip a shp file. I'm trying to create a coastal shp file for one region (NW France) from a ...
0
votes
0answers
29 views

GDAL/OGR in C++: Opening a vector file

So I'm making a vector file this way: OGRSFDriverH hDriver=OGRGetDriverByName("KML"); OGRDataSourceH hDS=NULL; hDS = OGR_Dr_CreateDataSource (hDriver, fname_dst, NULL); //I add layers ...
1
vote
2answers
243 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 ...
3
votes
1answer
50 views

Vector differencing fails in QGIS (due to geometric errors)

I was trying to correct the country shapefile of Uzbekistan for Gas flares: Input layer (the UZB_adm1) differenced by this layer. In QGIS the result was that the overlapping regions - where the ...
1
vote
1answer
79 views

GDAL/OGR in C++: Merge multiple vector datasets to single [closed]

I need to merge multiple kml files into a single one. I found that I could use "ogr2ogr -append" but I have to do it through c++ and my Google-fu hasn't been successful so far. So, any ideas? Also, ...
0
votes
1answer
64 views

Increasing size of buffer based on field in ArcGIS for Desktop?

I am using vector data from a CSV file and ArcGIS. I can use the Geoprocssing tool Buffer just fine, I use these parameters and ArcGIS does produce what I want, however it is way to small (my ...
0
votes
2answers
297 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?
1
vote
1answer
51 views

Can I make a multi layers pdf from a mapnik xml?

I am playing with mapnik and trying to export multiple vector files as one pdf with multiple layers. For the moment, my vectors get merged when rendering. Is there a way to keep each vector in a ...
3
votes
2answers
9k views

How to clip a line layer based on polygons with QGIS?

I have a line layer and a polygon layer. Both files have the same SRS. I want in a new shape file only the lines covered by the polygons. I tried in QGIS the Vector -> Geoprocessing -> Clip ...
23
votes
7answers
10k views

Nearest neighbor between point layer and line layer?

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...
1
vote
1answer
90 views

Viewshed plugin in QGIS doesnt work

I loaded DEM and Point data and as a result i just got black raster (still black after calculation). If I click intervisibility I cant see it like if line data is not there. I tried changing meters, ...
2
votes
1answer
765 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 ...
2
votes
0answers
35 views

How can I measure the distance between many polygon features and either another polygon or a line in QGIS?

I often have to manually measure the distance between a single site and other sites around it, but obviously this can get long-winded and I feel like there must be a much more efficient way of doing ...
1
vote
2answers
36 views

Resetting 'cat' column in GRASS?

I've got a regular polygon file that looks like this: Unfortunately, this file stems from a v.overlay so that the 'cat' values are are a bit messed up. I would like them e.g. to start in the upper ...
1
vote
1answer
23 views

Making buffer zone based on size of attribute using ArcGIS for Desktop?

Buffer zone isn't really the correct word, sorry, but I am not sure how to explain it. I want to make a circle around each attribute based of the size of the value, similar to a bubble map. However, ...
2
votes
0answers
60 views

Regridding vector values

I'm trying to regrid and interpolate vector values from WAM model output. I got WAM model netCDF output in rotated grid, I need to interpolate it to another grid which is some variant of LAEA ...
2
votes
0answers
83 views

QGIS 2.12 map composer issue with vectors

i am making a map that includes all kinds of vector layers; the map looks perfect in QGIS 2.12 Lyon as well as in map composer. None of the layers have scale-dipendent visibility; i have the following ...
1
vote
0answers
29 views

I clip a raster with a vector mask in qgis, the result is correct but its a little bit of, why is this?

On one side the result is "bleeding" over the vector on the other side its more than one raster pixel from the vector on the inside. How to correct this? http://i.imgur.com/d0v6mqt.png ...
0
votes
0answers
25 views

Spatial Join Points Vector with Raster Dataset using Arcmap

I have a points file of taxi drop off locations and a raster file grid. I am trying to get a count of each point on a raster cell. How do I go about doing that? It is like I am doing a spatial ...
1
vote
1answer
1k 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 ...
2
votes
2answers
103 views

Points that get created in the wrong order when using e.g. QChainage?

I have a polyline layer (road) that I want to use to get a point layer with 1 km between the points. I have tried both 'QChainage' and 'Locate points along lines' to do this. They both work, I get ...