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

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1answer
105 views

Openlayers Vector Layers eventListeners: how to specify different data without defining multiple layers

I have a map. It has two origins, and two destinations. The code for one origin is here: vectors_origin = new OpenLayers.Layer.Vector("Origin", { eventListeners:{ ...
6
votes
3answers
239 views

Create interactive map with no server

I have managed to build a great web mapping application using tiles created from GeoWebCache and a custom gridset, but I now need to add an overlay to the base maps. The only interactivity I need is a ...
2
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1answer
50 views

How to change layer transparency without changing border lines?

I have a raster image of elevations. I have added a vector shapefile that contains local political divisions. I want to keep the elevation colors, but I want to keep the black lines representing the ...
1
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1answer
39 views

Decoding Mapbox grid response

Can anybody give me insight into the grid json structure that Mapbox returns for use with overlays on tiles. What is the significance of !,#,$? Thanks in advance.
0
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2answers
380 views

Using OS Mastermap SLDs in QGIS

In an answer to a question asked by @Canningmister, @tjmgis posted an excellent answer Styling OS Vectormap Local in QGIS? about making OS SLD files work in QGIS. As an amateur user who uses QGIS to ...
2
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0answers
63 views

How can I improve the resolution of a vector grid made in north pole stereographic projection?

I've been struggling with this for a while and wondered if someone could lend a hand. I have a map which already has sampling points from centroids in a 35x35km grid that was created in north pole ...
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0answers
49 views

How to auto-fill a new point vector in a vector layer?

When I work in-situ I manually add points in my shape-file. I would like that when I add a new point some attributes would already filled with values calculated programmatically. E.g in my first ...
2
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4answers
143 views

High resolution and high detail vector GIS coastline product needed

What is the absolute best vector GIS coastline product available globally? I know of a great product for Africa (page 13 of this PDF ...
1
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1answer
163 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 ...
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0answers
38 views

grass plugin in QGIS all of sudden not working as expected

The previous week I was able to use the grass scripts in the QGIS 2.0.1 Dufour toolbox, but today they do not seem to be working. I am not sure where to place a '-c' which was a solution to the same ...
1
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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 ...
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0answers
55 views

Problem in removing dangles in road network [closed]

Im using qgis2.0 , In a given road network i have to remove dangles, for that what should be the tolerance to be added generaly. please help me resolve this issue
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2answers
123 views

MapServer: How to display and style a Text layer?

I'm trying to display a text layer using MapServer, but I'm kind of confused how to get it to display properly. When opening the .TAB file in a GIS application (in this case, MapInfo Profressional) ...
4
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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 ...
0
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0answers
47 views

Using Raster Data in a Vector Layer's table in QGIS 2.01

I have a vector layer containing point data representing floor levels. The attribute table contains: Easting Northing Floor Level I also have several water surface levels representing the ...
1
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0answers
50 views

Delete polygon underlap?

I am editing a layer in QGIS with severe polygon overlaps. Is there a way to delete the underlapping portions (i.e. the invisible parts) using QGIS? If I import the layer into GRASS using the ...
1
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2answers
122 views

Decrease resolution of vector shapes (polygon) i.e. reduce size and number of points in outer ring

I'm trying to get a kmz export down to less than 3 megabytes and am wanting to do so by reducing the number of points in my polygons' outer rings. I've seen this concept in action when it comes to ...
1
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1answer
159 views

Check if feature is selected (Openlayers)

I wonder if there is a way to check whether a pointfeature (OpenLayers.Feature.Vector) is selected. I read the API, but didn't find any solution. Any idea?
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0answers
49 views

OpenLayers - Features in cloned layer changes style with original feature

Please help! My situation is that, I clone() a "newLayer" from an "oldLayer" with its features. Both of them seems correct at first. But then when I tried to change the style of "featureA" in the ...
3
votes
1answer
120 views

Converting map image to GIS

I’m very new to GIS, and I’ve been reading a lot of manuals and information, but I thought I’d ask a couple of questions here. One of my major hobbies is drawing maps of a completely imaginary ...
1
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1answer
127 views

How To Show Percentages By Coloring Polygons in QGIS?

I am trying to produce a map with QGIS that has counties shaded according to the percentage of people born in a US Region. For example, counties with a high percentage of people born in the South ...
2
votes
1answer
78 views

heat map of density ratio of 2 layers of points

I have 2 vector layers of points: one with a point for each house in the city (thanks to osm.org), roughly equivalent to population one with a point for each case of cholera in the city I'm trying ...
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 ...
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0answers
76 views

Identify segments that share a last vertex with the first vertex of selected segment

This has been marked as a duplicate to Connecting line features and determining the length of the longest line but I believe there are some subtle differences. And to be honest I'm not an advanced ...
0
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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 ...
5
votes
1answer
125 views

LiDAR Feature extraction specifications/standards

I have vector data representing forests/trees/buildings that have been automatically extracted from LiDAR data. I am looking for specification/guidance for LiDAR derived products, or any standard for ...
2
votes
1answer
170 views

Possible workflows for shaded relief representation as vector

I am looking for a good workflow on how to represent relief on a map as vector (e.g. for further processing in Adobe Illustrator or Inkscape). My inspiration is the present google maps at zoom level ...
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2answers
74 views

QGIS point sampling tool really slow for polygons?

I have a large field of randomly distributed points (100,000 of them to be precise), and I'd like to get values for a variety of raster and polygon coverages for each point. I've been using the QGIS ...
3
votes
2answers
165 views

How to calculate distances between addresses and cities and coast line?

I am totally new to GIS, and so I apologize if my question is not clear enough. My basic problem is the following: I have about 160,000 Danish addresses with longitude and latitude for each address. ...
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
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
360 views

Convert vector data with irregular points (no grid) to raster with QGIS?

I am aware that how to convert a vector layer to a raster layer is a quite frequent problem and that there are many questions and answers dealing with it. However, none was helpful concerning my ...
2
votes
1answer
107 views

How to delete points which are close to each other?

I have a vector file containing thousands of points. Where points are within x distance from each other, I wish to delete one of the points and keep the other (either by snapping to one point, or ...
0
votes
1answer
90 views

How to increase symbol size of polygons when zoomed out?

I have many small polygon scattered. How do I increase size of polygons when zoomed out in qgis? As seen in the image the symbol appears to be lost when I zoom out. Note: I have created a thematic ...
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0answers
69 views

Google and Croatia WMS do not line up with shapefiles (500 meter to East)

I am working on a project in Croatia. I can use the WMS files from geoportal.dgu.hr/wms. These line up perfectly with the google maps. As project CRS I use HTRS96/TM which has become standard in ...
0
votes
2answers
57 views

v.what.rast trouble in GRASS GIS 6.4.2

I'm facing a problem using the v.what.rast comand. I'm trying to update the vector "canali" which represents some streams, with the slope value for every single point of the lines. The slope values ...
2
votes
1answer
205 views

How to calculate mean coordinates from big point datasets?

I know there are several questions related to speed issues in QGIS, but I am having problems when running Ftools. I have a vector with ~70,000 points in it. When I run the generate mean coordinates ...
0
votes
2answers
127 views

In grass v.drape works with points but not lines

I got an elevation raster map which I interpolate from a point cloud with v.surf.bspline. Then I digitize a couple of points in a new vector layer. With v.drape I'm able to get a height from the ...
2
votes
1answer
45 views

Conceptually, what's the ideal way to develop detour maps for a large number of nodes

I have a road layer of roughly 30,000 links. On these links, I have a total of 15,000 nodes that are sorted in a point layer. I'm trying to build a detour distance and routing around each asset in ...
1
vote
1answer
76 views

Snap mean coordinate to layer in QGIS and creating MCs for multiple shapefiles

1: I wish to create a mean coordinate for a group of points. However, I would like the new point to be snapped to the nearest point from the set of points used to generate it. How might one go about ...
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
81 views

please Introduce me a free 3rd party library appropriate for showing Geospatial information

Up to know I have used GDAL to extract raster data from geotiffs and then opengl's used to show that raster data. But when it comes to extract vector data with the help of ogr library, what library ...
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0answers
110 views

How to read vector datasets using GDAL library

Up to now, I have used GDAL in order to read raster information and geotiffs and show them with the help of OpenGL. Now I have a vector dataset, and by that, I mean I have the files with types: DBF ...
0
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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($) { // ...
2
votes
0answers
112 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 ...
0
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0answers
67 views

vector layer does not render points after modifyFeature

I'm implementing an appication with openlayers 2.12. Gets features from Geoserver after CQL search. Now, when the users clicks on one point/line/polygon, gets textual info via websockets (nodejs) for ...
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0answers
90 views

How to create a Layer from a list of points in PyQgis

I`ve developed an algorithm that generated an two dimensional array with points. Each subList of this array must be displayed as an polygon on the map view, and the recently created Vectors should be ...
0
votes
1answer
421 views

provide an alternative “label” when styling vector layer with openlayers

I'm using openlayers 2.12 and I am styling a vector layer using your typical new OpenLayers.Style({ Now, this layer does two things. First , renders polygons from Geoserver, so in the style I have ...
2
votes
1answer
63 views

Is it possible to display two categorical symbolizes for two different attributes in one layer alongside each other in ArcMAP 10.1?

I have a road layer that I would like to display attribute_1 = "speed" on top of the line segment and attribute_2 = "traffic_volume" below the line segment. For each attribute I would like to setup ...
1
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2answers
184 views

Custom filters (server side) for Openlayers Vector Layer

I have a vector layer in openlayers with source in GEOJSON (custom php server, which I have in complete control) and BBOX strategy. Vector points contain point sources which have different ...