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

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8
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130 views

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

Every thing is in the title... I have a vector region in GRASS. And I would like to generate a vector (a polyline) beeing the bostrophedon pattern which fill this region. In the picture bellow, I ...
5
votes
0answers
267 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. ...
5
votes
0answers
200 views

Convert Graphics to Vector in QGIS

I am wondering if there is a way to convert a graphic produced from symbology in QGIS to a vector layer (ie: shapefile). I have a point layer with bearing direction in the attribute table. Following ...
4
votes
0answers
219 views

QGIS: How to reverse vertex ordering in polygons

I am working with an Oracle spatial connection in QGIS through which I am accessing and editing a vector layer. I find that when I edit a geometry, the vertex ordering is reversed (to clockwise in the ...
3
votes
0answers
114 views

Joining csv file to vector layer in Processing modeler?

I am trying to join a simple csv file of values to a vector layer within Processing modeler. The match would be on an id held by both files. The csv file has no geometry. I can do this easily in ...
3
votes
0answers
225 views

Cross-browser marker animation in OpenLayers

Currently I'm trying to implement animated markers in OpenLayers. I'm using PNGs for the markers, set by the externalGraphic style property on an OpenLayers.Layer.Vector. I need to be able to make ...
3
votes
0answers
145 views

Is there a tool for automated quality assurance for vector data captured on raster data?

I wonder whether is any tool(or script) in ArcGIS or QGIS which allows to make an automated quality assurance for vector data captured on raster data? vector data on binary raster:
3
votes
0answers
339 views

How to Create a Vector Field from Separate u and v Data Files?

I am using Quantum GIS and trying to create a vector field using data from two separate netcdfs. One contains the u data, one contains the v data. Can this be done, and if so, how? Thanks. Jason
3
votes
0answers
1k views

problem with saving to esri file

I was using Wroclaw 1.7/GDAL 1.9(earlier release)/Grass 6.4/GSL 1.15-2 and started getting the following message when saving any item to esri format. "Export to vector file failed. Error: creation of ...
3
votes
0answers
224 views

Is there a way to create raster by interpolating point values using GeoTools 8.2?

im new in using GeoTools (8.2). I was able to create shp from asc file which contains my data. Now my question is is there a simple way to create (interpolate) a simple shapefile (only points) to ...
3
votes
0answers
1k views

How to get turn angle, line orientation and line length in ArcMap 9.3.1?

I am mapping and analysing animal movements using arcgis 9.3.1 along with Hawthorne Beyer's GME, and am trying to utilise the correlated random walk commands, but in order to do this I need to find ...
2
votes
0answers
63 views

How to tell if map service is fully vector or raster?

sorry if this is a duplicate, but I was wondering how to tell if a map service (in web browser) is vector based or raster based? What I think to understood so far is that Google Maps for example is ...
2
votes
0answers
28 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 ...
2
votes
0answers
39 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 ...
2
votes
0answers
63 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 ...
2
votes
0answers
23 views

Help getting a Mathematical Representation within a Layer's Attribute Table

I'v been playing around with Vector Coding and was wondering if there was any Plugins out there that might let me represent Vectors within a layer as it's Mathematic attributes in the Layer's ...
2
votes
0answers
25 views

Aggregate nearby points to develop equally sized regions in QGIS

I have a list of 4,500 points (lat, long, unique id, attribute). I also have a service territory which all of the points fall into. I would like to break the service territory (polygon) into 6 ...
2
votes
0answers
43 views

how to display 2 wfs layer at the same time from mapserver?

I have two wfs vector layers. When i show only one layer, it works. But doesn't work when i'm trying to show 2 wfs layers at the same time. How to show 2 wfs layers together? I'm using OpenLayers. ...
2
votes
0answers
402 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 ...
2
votes
0answers
90 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 ...
2
votes
0answers
114 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 ...
2
votes
0answers
168 views

Is there a decent algorithm in QGIS Process Modeller to create a grid?

I am using Process Modeller to automate merging several vector layers and then creating a grid to cover the extent of the merged layer. There are functions which already exist which are not listed in ...
2
votes
0answers
273 views

How to best intersect vector data with raster data?

I have Open Street Map [OSM] data imported so that I can access the geometry of buildings. I have also loaded SRTM digital height data from NASA from a GeoTIFF raster. I have projected the raster into ...
2
votes
0answers
266 views

How to render a transparent raster layer on top of one or more vector layers with PyQgis?

I been trying to render a map with a 3 vector layers and one raster layer. The idea is that the raster layer should be on top of the other 3 vector layers. The problem is that even when I add the ...
2
votes
0answers
72 views

Moving legend items up and down in QGIS

How can I change sort order in layer properties styles tab? The only way I've found is to change their labels and order by it.
2
votes
0answers
511 views

popular solution for display both tiles and vector data in android map app

We are planning to build a location based app like google map in android. We have some experiences in the PC development,that's to say we have a similar javascript api like google map javascript api, ...
2
votes
0answers
580 views

how to search a vector/wfs layer

I'm using Geoserver/PostGIS/openLayers I've succesfully set a vector layer. And now I'm trying to create a search functionality. But something goes wrong. First I set up the layer and add some basic ...
2
votes
0answers
201 views

Overlay Shapefile onto Geotiff

I have a Geotiff map and I want to overlay a Shapefile onto it. Ideally I want to specify a 'nice' style for the polygons e.g. have them opaque (for now all polygons should be the same). I want to ...
2
votes
0answers
471 views

Creating a sidewalk map for a walkability survey

If I wanted to do my own walkability survey of my city, what tools could I use? I have map data from OpenStreetMap, but I have to consider that streets have two sides (which aren't always accessible ...
1
vote
0answers
62 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 ...
1
vote
0answers
36 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 ...
1
vote
0answers
33 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 ...
1
vote
0answers
42 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 ...
1
vote
0answers
26 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 ...
1
vote
0answers
42 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 ...
1
vote
0answers
19 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
0answers
63 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 ...
1
vote
0answers
30 views

Select features intersecting a linestring in QGIS

I wrote a python plugin that grabs all (vector, linestring) features between two points on the map. At the moment, I select all features intersecting the rectangle around these two points, and then ...
1
vote
0answers
119 views

Merge multiple geojson-polygons

Lets say I have a very big image With a polygon in it: I want to polygonize this very big image with gdal polygonize. But the image is too big, so I dont have enough memory to polygonize that ...
1
vote
0answers
37 views

Tool, API of or code samples for calculating spatial similarity between Lines

I am migrating a database with a road network to an other external data provider. We have joined our own data about roadworks, temporary speed-limits, etc., using ID and linear referencing on this ...
1
vote
0answers
61 views

Does interpolation create a vector or raster?

I have been reading about interpolation and am trying to understand whether interpolation results in a vector or raster. Say I have a layer of points and I am interested in creating a raster that fits ...
1
vote
0answers
59 views

Trying to split a complex shapefile by australian states

Im trying to work with a 1:1 mill scale shapefile of the geology of Australia. When the whole lot is loaded in to QGIS (over 200,000 polygons) it will freeze and go to slow to work with. Ideally i ...
1
vote
0answers
70 views

creating composite raster tiles from multiple vector layers as new background map in QGIS

I have been patiently restyling OS Vectormap product to create a map background I'm happy with, which i want to now use as a background for a leaflet map using QGIS2leaf. I understand that performace ...
1
vote
0answers
39 views

Connect two contour line with calculated line lenght

Is it possible to make plugin for qgis like PEGGER for arcview 3.2? Problem is, how to make path over contour lines with a grade in percent Formula is: K= e*100/G*M ; K=10*100/0.08*10000=1.25m K- ...
1
vote
0answers
87 views

Calculating vector area in QGIS

I have calculated a viewshed (ZVI) in OpenWind and opened the raster in QGIS I have then converted the raster to a vector When I open the attribute table there are 4682 rows (features) and there is ...
1
vote
0answers
201 views

Render order of vector features in OpenLayers 3

In a web map application I have a vector layer from a GeoJSON source of country borders. The layer loads perfectly and interactions such as ol.interaction.select works fine as well. I want to style ...
1
vote
0answers
79 views

How to add vector KML data in an excel table

How do I take a KML (or XML) vector map saved on my desktop showing for example a election ward and then import it into excel as a data input in a field of data. I have information in excel for ...
1
vote
0answers
87 views

Determine lat/lon intersection on earth from point in space along 3d line

I have a known point in space with a lat,lon,alt. It has a camera with a line of sight and a angle of field of view. I can take the central point and calculate each corner vector of the field of view, ...
1
vote
0answers
23 views

When trying to save a vector in QGIS a blank dropdown window appears

I am learning and using QGIS Brighton and have hit a obstacle. Everything has been going fine until I started using the experimental generalizer to smooth the contours that I had extracted from some ...
1
vote
0answers
18 views

QGIS rasterize a styled layer

I disabled information from a vector layer with a styledefinition. Is it possible to rasterize only the styled information in QGIS?