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

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488 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. ...
3
votes
1answer
179 views

How to calculate the percentage of a Line through Polygons?

I have a straight line which runs through a bunch of polygons, which don't have spacing between them (border to border). Is there an easy way with QGIS to calculate which polygons it passes and by ...
3
votes
1answer
913 views

adding polygon to database in openlayers

I want to add a polygon to the database. I used the following code. The problem is that I am to able to save in database. Whatever polygon I draw on map it gets save temporary and as soon as I reload ...
3
votes
1answer
361 views

MapServer Symbol with Two Colours

I'd like to symbolise a point dataset with a square (or circle) using two colours. This is useful for displaying values collected on both sides of a road (for example). I created two symbols, a ...
3
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2answers
201 views

Dissolve column based on attribute in another column

I have 3 columns within a polygon layer I'm working with. Column 1 = Landowner, 3 different values Column 2 = Parcel, N different values Column 3 = Management type, 5 different values I would like ...
3
votes
1answer
455 views

How to access the icon of a feature retrieved from text in a vector-layer?

I`m using OpenLayers to show POIs on a map. These POIs are loaded from a textfile and I`m using a Vector Layer to get it onto the map - works great. Now I want to use the cluster strategy to have ...
3
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1answer
956 views

Splitting lines at a specified distance

Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
3
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2answers
2k views

How to query which features of all vector layers intersect with a given bounds?

I am writing a Openlayers map app, and wondering whether there's a better practice to query which features of which vector layers intersect with a given bounds.. It's certainly not a good idea to ...
3
votes
1answer
917 views

Why is Openlayers KML-layer undefined when using permalink

I am working on Openlayers to dynamically load KML tracks on map. I want it to load filtered KML everytime map is moved or zoomed based on viewport and zoom level. I got it working with code below, ...
3
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2answers
493 views

Linear referencing: Assigning RouteIds to polyline feature class

I have a Linear Referencing Route System in ArcGIS Geodatabase format (polylines with M values) and a separate polyline feature class of short segments (called TMC) that do not have RouteIds ...
3
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1answer
1k views

Openlayers Add features performance for 3000 lines

We would like to implement the function of Addfeature in openlayers to draw lines and push them onto a vector layer, and overlay this layer onto open street map or google map. Those lines are draw ...
3
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1answer
4k views

Reproject a vector layer (EPSG:27700) using WFS onto a googlemaps background (EPSG:900913)

I have the following HTML-javascript code and i have problems reprojecting the vector layer (WFS) from EPSG:27700 (British National Grid) to EPSG:900913 (googlemaps). I managed to project the WMS ...
3
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1answer
26 views

QGIS Convert bathymetry shapefile from fillable to strokeable

In Java I would like to stroke the bathymetry depth lines instead of filling the area. I'm starting with the Natural Earth Bathymetric Data: ...
3
votes
1answer
46 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 ...
3
votes
1answer
215 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 ...
3
votes
1answer
121 views

Representing overlapping polylines in QGIS

I have several shapefiles representing bus lines with different colors for each segment, however, because the lines are exactly superposed, only the shapefile on top can be seen. Is there a way to ...
3
votes
1answer
98 views

One vector data layer with different styles in QGIS

I have one layer of vector data that I would like to show in two different styles. Is there a way of accomplishing this in QGIS? I've solved it now by duplicating the the vector layer and add ...
3
votes
2answers
60 views

Pyqgis How to merge all the active layers? or layers in the registry?

I was wondering if there is a way to merge multiple layers. I actually would like to merge all layers in the registry programmatically, all of them are point layers and have the same fields. I have ...
3
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2answers
336 views

ArcGIS 10.2.2: How to clip vector data from raster data?

I have two files: National land cover data (raster) HUC 8 (vector files of watersheds) Both are national scale but the HUC 8 takes up a larger geographic region than the raster set so I want ...
3
votes
1answer
225 views

Memory Vector Layer Corrupted?

I was working with a large data set that had data for roads, rivers, railways, etc. all together so I decided to break the different data out so I could label it differently on the map and check each ...
3
votes
1answer
2k views

Display list of OpenLayers Features which are currently visible on screen

I have an OpenLayers map a few thousand Points of Interest. These POIs are Vector Features rendered in a Vector Layer. We are loading the POIs once in order to minimize load on the server. Next to ...
3
votes
1answer
1k views

Split vector layer by field name

I have a vector layer of 108374 lines I want to split the vector layer into field names of the layer, which is 17. Now, I want to create a new vector layer containing one of the field names e.g. ...
3
votes
1answer
2k views

How to get attributes of overlaying polygon layers by a spatial query?

I am new to QGIS and would like to merge selected data/attributes out of the attribute tables from overlaying vector objects on different vector layers without creating new additional layers. Is ...
3
votes
1answer
798 views

OpenLayers 2.12 + click handler + get the name of the vector

Basically, I add several vector layers (KML content got from jQuery GET) in this way: var layer1Vector= new OpenLayers.Layer.Vector('activeInfo'); layer1Vector.addFeatures(featuresLayer1Vector); ...
3
votes
1answer
1k views

OpenLayers - Vector Layer and Google Maps - vector layer and google layers don't seem to be in sync when zooming on Chrome

I am working with a Google Layer and a vector layer in OpenLayers. I was wondering if anyone else noticed any problems with Chrome displaying Google Maps layers on OpenLayers? It seems that when I ...
3
votes
1answer
451 views

Sum up area left “underneath” polygons in QGIS?

I have an area shape layer and multiple other area shape layers. Now I would like to calculate how much space (square kilometers or percentage of area) of the polygons of this area layer is NOT ...
3
votes
1answer
597 views

turning multiple vector layers into one raster in arcgis 9.3.1

I want to make a raster out of the multitier view I have in ArcMap 9.3.1 . The layers in my ArcMap come from several datasets. I know there is a 'Feature to Raster' tool, but it converts one layer at ...
3
votes
1answer
1k views

geometryType property of Vector Layers in OpenLayers

ORIGINAL: I have a couple questions that are focused around the geometryType property with vector layers. When you create a vector layer you can set the geometryType property to limit the geometry ...
3
votes
1answer
499 views

How to sensibly digitise this raster, scriptably, in ArcGIS

I have the raster below which I want to convert to a set of vector lines: As you can see, there are small breaks in the lines and some bits are double-width. I want to be able to reliably import ...
3
votes
2answers
160 views

Add rectangle polygon

I have a polygon shapefile layer. I want to add a rectangle polygon (just like in Arcmap), and another one using the previous polygon edge. I need it to be accurate, my hands do not meet this ...
3
votes
1answer
219 views

Looking for Android, offline, mobile app for field campaign?

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 ...
3
votes
1answer
361 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 ...
3
votes
1answer
72 views

Speeding up raster to point set function

I have written the following function that takes a raster (always non-skewed) and returns a set of points. As I'm executing it millions of times in my queries, I'd like for it to be super-optimized ...
3
votes
1answer
262 views

How to create a line layer which connects a point layer to a line layer?

In the map shown below, I have manually created the dummy lines (in green). Using python, and without using PostGIS or sextante, I would like to automate the creation of these dummy links between a ...
3
votes
2answers
213 views

How to create a hectare raster from vector input data in QGIS

I have a vector file containing points with an attributed value (no. of employes at that location). I need to create a hectare raster with the sum of employes for each grid cell. I'm using QGIS and ...
3
votes
1answer
367 views

Visualizing Spatial Query

I'm new to GIS applications and trying to figure out what options I have for visualizing spatial query results that combine raster and vector data using OpenLayers/GeoExt/GeoServer/PostGIS. A ...
3
votes
2answers
335 views

Creating catalog of vector layers using ArcGIS Platform?

Is there a way to create a catalog of vector layers in ESRI? We have thousands of tiles of 25cm contour data which we need to individually find and add to maps. It would be so much easier if there was ...
3
votes
1answer
871 views

How to get the distances (shortest path) between all pairs of points in the river network?

I have 2 vector shapefiles (one line, one point), and I have tried at least 4 ways to try to get the distance matrix at one time (and most concern the directions of each river segment) quantum ...
3
votes
1answer
186 views

Creating a vector based design from a raster database

I have a raster table that I've created using Postgis raster. It has 365 records and the table looks like this: +-----+------------+---------+------------+ | rid | rast |filename |date_of data| ...
3
votes
2answers
2k views

Dynamically adding features with cluster strategy

I am trying to dynamically add features to a vector layer, and use cluster strategy to group those features accordingly. I am able to do this for the first set of data that gets loaded on the map. ...
3
votes
1answer
918 views

OpenLayers polygon fill on IE has black shading

I have an odd problem on with OpenLayers on IE6, IE7 and IE8. A newly drawn polygon has odd black shading. In fact, even the line (stroke) has the same black outline. Works great in Firefox, ...
3
votes
2answers
921 views

How to combine polygons in a vector with GRASS?

I need to combine polygons of similar geological classes which are stored in a vector file called geology. I was looking for somethiing like "union selected features" or similar. In the GRASS Book ...
3
votes
1answer
2k views

Extract parcel layers from vector pdf

So, I have an interesting problem... I have a PDF file which has over 100 pages and each of these pages is displaying a map in vector format. By using some third party program I was able to find out ...
3
votes
0answers
39 views

Still no fictional geographies in some GIS format? [duplicate]

I'm actually reviving Are any fictional worlds available in some GIS format? from 2011 as I'm hoping the Game of Thrones fever has boosted people's interest in drawing fictitious countries in some GIS ...
3
votes
0answers
111 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
2answers
345 views

Comparing 2 polygon shapefiles for differences [duplicate]

I have 7 shapefiles, each representing a year, all containing lots of polygons (c. 500,000). My aim is to take any 2 of them and compare how they have changed in terms of size and shape of polygon. (i ...
3
votes
0answers
218 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
1answer
150 views

Are there plans for improving performance of vector files in QGIS? [closed]

Does anybody know if there are any improvements planned pertaining to the performance of vector files in QGIS? Right now, a 1 GB file with contour lines needs several minutes to open. In addition to ...
3
votes
0answers
143 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:
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0answers
319 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