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

learn more… | top users | synonyms

1
vote
1answer
38 views

QGIS: Line to polygon conversion

Currently we are working in a geological project..in which all the Contacts, Linear & some other geological features have to be captured. The thing is most of the features have to be Captured as ...
2
votes
1answer
143 views

Creating buffers that will not overlap in QGIS

I am dealing with a .shp with a number of points in it. The distances between points range from ~300m to 5km. I wish to create a 1 km buffer around each point with as little overlap as possible. Each ...
0
votes
1answer
131 views

How to draw a custom map on top of base layer

I'm looking for the easiest way to draw a custom layer and export it as a tile cache. Basically what I would like to be able to do is load a base layer, and then draw objects and annotations on top ...
1
vote
1answer
66 views

Stamp out and transfer values from one overlayed vector layer to another

I have a vector layer with administrative boundaries and another vector layer with postal code boundaries, which are more precise/smaller entities/objects. I now want to transmit the values of one ...
1
vote
2answers
32 views

Techniques for Filtering the Attribute Table in QGIS's Print Composer

For the legend of a trail map I'm working on I'd like to show the trails and their lengths. I have this data in the table. The problem is that not all of the features (lines) have a name or length. ...
2
votes
2answers
107 views

Georeference vector linework

I'm new to GIS and a lot of searching didn't answer my specific question so far, so I hope someone can help me here. What I want to do is creating a small web application to visualize election ...
0
votes
1answer
24 views

Select all features close to clicked

I have an openlayers map with more then 20000 features not in wms, only in vector layer. I have a control to select features, but sometimes it's really hard to select, specially the lines, and also ...
1
vote
1answer
19 views

How to Warp vector file based on control points in ArcMap?

I have a very comprehensive polyline file that, when compared with imagery, is obviously offset by a few hundred meters, but the offset varies from one area to another. It would be easy for me to ...
0
votes
1answer
31 views

Producing gradients between shapefiles and using original boundarys as isoclines (lines)

to produce a bathmertical map of a river bed I draw shapefiles showing the different depths based on satellite images taken during different tidal levels (deepest, 2nd deepest, 3rd deepest, shore ...
0
votes
1answer
286 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 ...
0
votes
2answers
10 views

Adding time stamps to animation slides with OSS tools

I would like to create an animation with time lapse values printed on the PNG file. For this purpose I have created in QGIS a vector layer that stores timestamp and temperature value pairs for various ...
0
votes
1answer
22 views

Rasterization in different bands

I have a set of vector based shape files, representing different types of ground coverage in a city (for ex: roads, buildings, open field,...). For the algorithm that I want to run on it, I need just ...
3
votes
0answers
31 views

Looking for a mobile app for a field campaign with specific spec

In the frame of an international project in agriculture monitoring, I have to propose a mobile app that will be used as a reference for field working. The minimum requirements of such an application ...
0
votes
0answers
23 views

How to raster vector- and shape-files correctly

does anybody know how to convert vector- and shape-files correctly? Doesn't work with tab Raster/convert/vector to shape files. The output always contains strange input-data (wrong and strange ...
4
votes
0answers
24 views

Projecting polygon when calculating its area? [duplicate]

I have a broad range of polygons (in vector format and in SpatialPolygonsDataFrame class), some going east-west, others going south-north, while even others span polar regions or very large ranges as ...
0
votes
1answer
33 views

why can't i export geometry data from a shapefile?

I saved the layer using "vector save as" box but even when adding GEOMETRY=AS_XY in the layer box, the csv only showed the id and no gemetry data.
3
votes
2answers
324 views

How to export 2d vector graphic from Arcscene?

I need to know how to export 2d vector graphic from ArcScene so I can edit it with illustrator. I've tried changing the options when I export 2D scene as AI file or PDF file, but they always remain as ...
2
votes
1answer
40 views

Why do layers appear in the wrong order in QGIS 2.2?

I have a problem with in which order my vector and raster layers appear in QGIS. I have raster that I want to be the background of my other layers (vector). I place the vector layers on top in the ...
0
votes
2answers
68 views

Show only some buildings

How do I show only some buildings? I only need to show 3 cabins in the forrest, but not every house in the whole village around, and the city close by. Maybe some of the symbol buildings in the city ...
1
vote
0answers
17 views

Generalisation Help for large amounts of Shape layers (QGIS)

I'm sorry if someone has asked this already I just haven't been able to find the right thread. I'd like to re-explore/update: What are the existing solutions to automate generalisation/simplification ...
3
votes
1answer
140 views

How to sum up all field values in QGIS modeler

I am building a model to generate two zones around a point, a 250m-buffer, and a ring of 250 to 1000m, where i recalculate values from an other layer according to the intersections share. The purpose ...
0
votes
1answer
430 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
vote
2answers
31 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
14
votes
3answers
5k views

How do I load OSM vector data in QGIS 2.x?

In QGIS 1.8 I used the openstreetmap plugin to request data from the server, or open a .osm XML file, which produced 3 layers (polygons, polylines and points) in QGIS. This was great (give or take the ...
2
votes
1answer
1k views

How to deactive Vector Selection In OpenLayers wms features

This is my sample code and work fine :), But I have a little problem, I'm using multiple layer (WMS), when I zooming the layer will be shown or hidden. In my example bellow when OpenLayers level zoom ...
1
vote
0answers
18 views

Calculating Percent Overlap Between Distribution Maps

Hello there, I am currently trying to calculate the percent overlap (basically the total amount of overlap where these two species come into contact) between Lithobates catesbeiana (first image) ...
0
votes
1answer
15 views

vector file is used by two mapsets at a time in grass gis

i want to study about vector processing.if a vector file is used by two mapsets at a time, which one will be saved first and why.if a team want to work on the same set of shape files, what is the ...
4
votes
1answer
104 views

How to add tree height values to raster / vector data?

I am new to working with raster data and I am trying to teach myself a few things. I have what I think is a simple problem but I can't seem to figure this one out after a few hours of searching Arc ...
1
vote
1answer
462 views

Drawing pie charts with vectors on OpenLayers?

Is anyone got any examples of drawing pie charts with vectors as markers on OpenLayers ? Cheers,
0
votes
1answer
148 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
vote
0answers
52 views

Editing QGIS point layer: retrieve attributes of intersecting line layer

I'm creating a custom editing form using QGIS 2.0 and would like to modify the mouse event when creating a point. I've gotten a start by reading this thread: How to programatically check for a mouse ...
0
votes
1answer
74 views

Counting raster points within boundaries in another layer?

I know this question is similar to some out there, but I have tried all the 'solutions' and none of them are working for me. I am using the latest version of Qgis. I have a raster layer with ...
0
votes
2answers
279 views

OpenLayers: WMS layer above select-controlled vector layer?

Is it possible to display an image layer (WMS or Image) above a vector layer with activated SelectFeature control in OpenLayers? The image layer (radar returns) contains only sparse, semi-transparent ...
4
votes
1answer
191 views

What does vector tiled map mean?

I'm working on an application that renders geoJSON into OpenLayers map. The idea is about not having PNG images downloaded from external services (OSM or Bing) but having geo information in geoJSON ...
4
votes
2answers
413 views

Vector Mapping for iOS?

Are there any vector map data providers with API's, that i can use to build my app on iOS natively (not on a webview). Specifically im looking for: For a library/framework that uses existing map ...
0
votes
1answer
37 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 ...
0
votes
0answers
29 views

how to easily serve vector layer with extra attributes for openlayers

On a website I'd like to show an openstreetmap with buildings colored by a certain feature (tag). So far I was able to extract the buildings for a bounding box, save them as an osm file and load it ...
4
votes
1answer
121 views

Loading a multipoint shapefile in R

This issue has only been raised in the community once, two years ago, to the best of my knowledge. I think it's high time to raise the issue again! readOGR, from the rgdal package, cannot handle ...
1
vote
1answer
162 views

pyQgis in stand alone script, vector loading error

I am trying to use the Qgis functions in a stand alone Python script. I m running Mountain Lion OS, 2.7 Python & the Qgis 2.0.1 Dufour. My main problem is that I cannot get started - I cannot ...
4
votes
1answer
56 views

Generating a vector contour map of fictional terrain

Originally I had asked this on the Graphics Design SE but after some realization of the question I was asking, it's probably better to ask it here. I'm making a fantasy world map in illustrator that ...
0
votes
2answers
118 views

How to Resolve Inconsistent OpenLayers vector position Over Google map

I have an OpenLayers map with a Google base layer and an OpenLayers vector layer on which people can draw their own bounding boxes using the DrawFeature control. I have found that, as you zoom in, ...
1
vote
1answer
57 views

map can only have one feature, after user click

I'm using openLayers 2.13.1. I have a map wih a vector layer and Editing tools. I want the map to have only one feature even if the user keeps adding. So I want the new feature to automatically ...
1
vote
1answer
50 views

CartoDB map in openlayers

Is there a way that i can upload my CartoDB map in Openlayers as a WMS layer or Vector layer. Here is the my CartoDB map link. http://cdb.io/1nxdrpf
0
votes
1answer
18 views

Trace vector map from GeoTiff, Garmin

My goal is to create a vector map for my Garmin GPS by tracing over a topo raster. The vector data would be exported in ESRI SHP format and later converted for Garmin. So far, I can load the geo ...
0
votes
0answers
25 views

Positional error of line features

Does anyone know how to model the error in the spatial location of a line? I think Survey Analyst extension in ArcGIS had a possibility to construct ellipse errors but it is not available any more. Is ...
0
votes
0answers
14 views

GRASS GIS - v.select- ERROR: bad allocation -

I'm quite new to Grass GIS. I have two vector maps, one of a grid (each grid cell is a polygon) and one of a much larger polygon. I've been trying to select the grid cells that lie completely within ...
1
vote
2answers
55 views

QGIS 2.0 Automatic generation of a vector layer out of a point layer

I am an environmental engineer and the aim of my QGIS 2.0 project is to visualize the results of a sewage water system inspection. In a first step I included the hoppers from a csv file and added a ...
0
votes
1answer
34 views

Invalid geometry message when using Difference tool

I am using the Vector \ Geoprocessing \ Difference tool to get the resulting area when taking a) current ground disturbance away from b) historic total ground disturbance to give c) what has been ...
0
votes
0answers
36 views

Turn vector layer in raster layer based on cost

Hy, I am trying to rasterize some vector layers into raster layers and I know this is possible with QGIS by using the rasterize function in the raster menu but I don't know how to do the following ...
1
vote
1answer
48 views

QGIS combine Vectorlayer and Rasterlayer to one shapefile

I have to create some Thematic Maps, especially Choropleth Maps on Matlab. Therefore i've found a shapefile which I can use, but need to draw some lines there. I've imported my shapefile as a Vector ...