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

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1answer
613 views

Why does QGIS hang when I try to create a vector grid?

I am working in open layers plugin.i need to project the satellite data with respect to vector data shape file i am having .for that Andre Joost suggested to create vector grid with vector data ...
3
votes
2answers
423 views

Overlay Vector Layer on Raster Layer

How can I overlay a Vector Layer on a Raster Layer and assign NoData Values on the Raster where the Vector Layer does not cover the Raster Layer? (preferable with ArcGIS)
3
votes
1answer
925 views

How to convert shapefile to vector emf?

I want to convert a shapefile to an EMF file. The EMF file must be a vector image, not a raster image. Please suggest to me some good packages or tools. Thanks in advance.
3
votes
3answers
637 views

DXF to georeferenced SHP

I know how to set projection and georeference bounds of scanned TIFF file, by using gdal, but I don't know how to do the same for vector file. For example I georeferenced TIFF file by using this ...
3
votes
3answers
194 views

How can I draw squares in PostGIS layers at different angles?

I am trying to draw two squares on a 45-degree angle and then merge them using PostGIS to edit. QGIS can draw squares but only on a perpendicular plane (eg, 0, 90, 180), and I need to be able to draw ...
3
votes
1answer
328 views

Measurement units not returned in project CRS units

I am attempting to calculate area of country polygons using the field calculator. The layer in question is unprojected WGS84, but I have set the project CRS to World Equidistant Cylindrical ...
3
votes
2answers
2k views

How to subtract Geometry Point Polygons in OpenLayers?

I have two json arrays, one for background polygon and one for other polygon. And from them, I got two polygon layers. backgroundLayer = new OpenLayers.Layer.Vector("Background Layer", {styleMap: ...
3
votes
2answers
1k views

Stylized map workflow: Illustrator to Google Maps / OpenLayers

The aim My current aim is to create a series of (heavily) stylized diagrams and maps. I'm not very familiar with any GIS software, so my weapon of choice would be to use illustrator for creating the ...
3
votes
3answers
671 views

How do I draw on a vector map in GRASS?

I have a vector map that has two lines. I want to have the two connected. Is there a way for me to draw a line to connect the two? I am using GRASS gis by the way. The two lines that I want to connect ...
3
votes
2answers
1k views

Working With Vector Product Format (VPF) - APIs, etc

I've been looking around the Internet for information about Vector Product Format. I want to put together a project that can read Digital Nautical Chart (http://msi.nga.mil/NGAPortal/DNC.portal), ...
3
votes
1answer
107 views

Where to get the modern Constellations as a vector File?

Does anyone know where I can get a vector version (shapefile/TAB) of the modern star constellations for the entire sky? Wikipedia has a SVG - ...
3
votes
1answer
81 views

Add more info in the attribute table after executing “Line intersection” in QGIS

I have executed the "Line intersection" tool on a road shapefile. This is under Vector > Analysis Tools > Line intersections. I get an output with attribute table having just two columns: type_1 ...
3
votes
1answer
114 views

How to horizontally align irregularly shaped point symbol to vector layer in QGIS?

Fairly new to QGIS and searching a method to graphically align my point symbols in the direction of the vector. The symbol represents a water valve in an irregular shape in close proximity to a vector ...
3
votes
2answers
282 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
150 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
749 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
287 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
votes
2answers
150 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
396 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
votes
1answer
828 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
votes
2answers
430 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
votes
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
308 views

Openlayers vector layer don't draw well on chrome (single tile)

I have singleTiled layer in OL (using chrome). The layer don't draw completely unless I pan the map slowly to the south (here is example how the layer keep drawing itself each time I pan) : ...
3
votes
1answer
682 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
748 views

How to remove a vector QgsVectorLayer from QGis python plugin

I managed to add QgsVectorLayer in QGIS through a python plugin, for example: vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName()) But how can I remove it?
3
votes
1answer
586 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
2answers
5k views

Calculating the minimum distance between points and polygons in QGIS

I have two vector layers: one point and one polygon and I want to calculate the minimum distance of each point from the polygons (ie the distance from the closest point of the closest polygon). Is ...
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
684 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
votes
1answer
488 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
759 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
3k views

Relabel Vector Points in OpenLayers

I have created two labeled vector points on an open layers map. I'm trying to change the label text dynamically. I tried changing the values where the stylemap gets the values from and calling ...
3
votes
1answer
3k 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
votes
1answer
466 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
104 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
196 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
59 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
174 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
159 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
241 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
190 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
665 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
1k views

How to use a sld file with Openlayers using OSM data?

My app, made with openlayers, displays building data called from overpass api. var data_url = "http://overpass-api.de/api/interpreter?data=(way[building](bbox);node(w););out body;"; //main working ...
3
votes
1answer
145 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
1answer
381 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
787 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
727 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
1k 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
49 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 ...
3
votes
2answers
170 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 ...