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

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4
votes
2answers
486 views

Is it possible to generate a vector polygon from a polygon on a raster image?

I have a raster map which I have extracted from a government report providing flood extent return frequencies. I want to 'snatch' these flood extent polygons (i.e. convert to vector) and I was ...
4
votes
3answers
9k views

Hover/Popup feature problem

im really having an issue here. I am trying to realise a map where i can hover over the features and they get highlighted (works), then i want to be able to click them (works) , i also want a div to ...
4
votes
1answer
288 views

How to know contents of column names in GRASS?

I am using GRASS to extract a specific area from a vector map. Here is the script that I am running: v.extract PHL_map out=makati where="AREA_NAME = 'Makati" The problem is, I don't know what are ...
4
votes
4answers
2k views

Openlayers WFS Vector Layer Rules dont get applied

i have a script which applies rules to wfs.vectors. the script works fine in firefox and all the rules get applied, but somehow when i open the same file with the internet explorer 7 / 8 , only the ...
4
votes
1answer
218 views

Raster to vector with gaps in Landsat ETM

I need to find size of water area from a raster (jpg) using QGIS 1.8.0-Lisboa. The raster is a Landsat image with gaps of data in it. I used Polygonize, but the output file shows wrong polygon size ...
4
votes
2answers
2k views

Measuring the distance between lines and points in QGIS

Using QGIS - I have a vector of fault lines. I have point data in the form of a csv which I have also loaded into QGIS. I need to know how far each point is from the nearest fault line then enter ...
4
votes
1answer
5k views

OpenLayers, zoom to vector layer extent

It seems quite simple thing to me, but I get an error. map declaration map = new OpenLayers.Map('map_element', {... projection : _projObj.mercator, displayProjection : _projObj.wgs84 } layer ...
4
votes
3answers
3k views

How to combine information from raster and vector layers?

in QGIS I have 1 raster-layer (elevation) and 1 vector-layer (administrative units). Now I would like to be able to query one of the administrative units and see the mean and min/max of the elevation ...
4
votes
1answer
614 views

How to extract features from a vector layer?

I have a vector file containing the river lines of an area. I want to extract a specific water line from the vector. I used: v.db.select but it only displayed: ...
4
votes
1answer
119 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 ...
4
votes
1answer
90 views

Suggestions for vector format for contour map

I've been trying to create a contour map of a DEM and I've been running into some technical problems. I want to avoid artifacts, so I'm using a DEM of the entire area. This means the size is rather ...
4
votes
1answer
79 views

Reduce number of vector field arrows in qgis

OK, now that I have figured out how to get my vector fields in qgis, I can't figure out how to reduce the number of vector arrows on the map. Is there a setting for how many vectors are sampled? ...
4
votes
1answer
334 views

Generate centroids for vector polygons based on raster and land-use data using QGIS

Although QGIS has the ability to generate centroids for polygons, I am not sure how to generate centroids based on land-use development using raster data. Here's an example of what I'm trying to do: ...
4
votes
3answers
1k views

Calculate neighborhood statistics for polygons?

I've been searching around for the answer to this (including here) and have yet to find it. I'm interested in finding out how to calculate a 'neighborhood sum' for vector, polygon data. I am aware ...
4
votes
1answer
187 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 ...
4
votes
2answers
331 views

How to delimit hinterland boundaries among multiple city centers?

I need to delimit city boundaries basing on centers'magnitude. CenterA's employment/CenterB's employment = (Distance from centerA to break-point E/Distance from centerB to break-point E)^2. AB=AE+BE. ...
4
votes
2answers
488 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 ...
4
votes
1answer
94 views

Extract Z information from different vector layers in ArcMap 10.1

I have 2 different vector layers, Layer A detailing the area of different polygons and Layer B having similar size polygons with z values instead. I would need to combine Layer A with Layer B so that ...
4
votes
1answer
290 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
4
votes
2answers
1k views

OpenLayers - Get features inside a polygon

In my OpenLayers map I allow users to draw an ad-hoc polygon vector. Then I need to get all the features from a WFS vector layer that fall within the ad-hoc polygon. Here is the code I have that ...
4
votes
1answer
394 views

How to export 2D vector graphic from ArcScene to Illustrator?

I need to know how to export 2d vector graphic from ArcScene so I can edit it with Adobe Illustrator. I've tried changing the options when I export 2D scene as AI file or PDF file, but they always ...
4
votes
1answer
409 views

Analysing Information By Vector Grid

I have two vector line datasets and wish to compare the line lengths. While I have already compared the sum of the lengths, I'd like to conduct further analysis down to 250m, possibly lower. I'm ...
4
votes
1answer
704 views

How to prepare SVG images for presentation in OpenLayers?

I have a collection of SVG vector images I need to display on a map, probably using OpenLayers/KML. Is there any way to convert a vector image from SVG to KML? Or would it make more sense just to use ...
4
votes
1answer
1k views

GDAL - creating vector from raster

[SOLVED] Good day! I'm looking at either gdal_contour or gdal_polygonize.py to create a vector layer file from a raster file. I can create the vector file using either method, but it's upside down ...
4
votes
0answers
27 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 ...
4
votes
0answers
97 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 ...
3
votes
2answers
4k views

How to connect OpenLayers to PostGIS data?

I have read in OpenLayers how to load KML, GeoJSON etc. vector files in OpenLayers. But how can I connect to PostGIS data. If not, why should I upload my data to PostGIS then instead of directly ...
3
votes
2answers
185 views

Is there a shortcut in GRASS for importing vector files?

Is there a keyboard or command shortcut in GRASS for importing vector files? If you know link where I can find maybe whole list of shortcuts for GRASS, that would be awesome. Thank you.
3
votes
5answers
2k views

Export shp spatial data to Corel

Hi I need an printable administration map of a country. I would like to use it in Corel Draw for some colour manipulations and poster printing. I have found the map on http://www.diva-gis.org/ but it ...
3
votes
2answers
670 views

How to find the middle point of a line in QGIS

I am trying to locate the coordinates of the middle point of a line feature in QGIS. I tried searching online but can't seem to find an easy way to do this.
3
votes
1answer
1k views

How do I find vector line bearing in QGIS or GRASS?

How can one extract the bearings from a set of lines in a vector file? I'm trying to find the bearings of several straight vector line segments (simplified contour lines, actually) and can't figure ...
3
votes
4answers
2k views

Scriptable way to merge polylines that join in ArcGIS

I have a number of polylines (around 9000), a number of which have one or both ends touching another polyline. I would like to merge these ones together into one polyline - thus reducing the number of ...
3
votes
2answers
158 views

restrict quantity of features displayed with OpenLayers

I have 14000 point vector features in the map. Displaying them all is very slow (renders at like 1 fps in chrome). How can I tell Openlayers to only display a subset of them, for example features ...
3
votes
1answer
145 views

Creating a radius of influence around points

I have a vector file of points. What I need to do is create a circle with a radius of 12km round each point. Would it be possible to then find out what percentage of my total map is covered with ...
3
votes
2answers
393 views

Creating seperate layers out of one big polygon shape by using attributes

I try to explain may problem. I have a big polygon shape (> 200 fields). I have the owners of these fields in a column. I need the seperated shapes for each owner. Is there a tool to do that? Is it ...
3
votes
4answers
3k views

Looking for an annotated vectorial map of the world

I'm looking for an annotated vectorial (PS/SVG/...) map of the world (+countries). Wikipedia contains many vectorial maps (e.g: http://commons.wikimedia.org/wiki/Category:Blank_SVG_maps_of_the_world ...
3
votes
2answers
103 views

Obtaining OS MasterMap time series data

I am trying to do a research project on changes in Land Cover in a London borough over time. I have access to OS MasterMap data through Digimap (the service that provides this data to universities in ...
3
votes
2answers
74 views

Is it possible to add house numbers using the Mapbox Street Vector Tiles source in Tilemill2?

Title says it all. Does anyony know if the house number is included in Mapbox’ vector tiles, and if so how to access it for styling? Thanks for any advice!
3
votes
1answer
20k views

What is the difference between Vector and Raster data models? [duplicate]

From: http://support.esri.com/en/knowledgebase/GISDictionary/term/vector%20data%20model vector data model: [data models] A representation of the world using points, lines, and polygons. Vector ...
3
votes
1answer
1k views

How to get all Vector layers from OpenLayers map?

OpenLayers.Map object exposes a method call getLayersByClass. How do I use this method to retrieve all of the Vector layers from the map? I tried map.getLayersByClass("Vector") but this returned an ...
3
votes
2answers
99 views

vector layer, no more editing is allowed

I have a polygon vector layer with already 529 objects but without any attributes so far and now I get the message that shapefiles without attributes are treated as write protected. What can I do to ...
3
votes
1answer
213 views

Halo in OpenLayers (Line, Vector)

How to make a halo around the line of one pixel? For example, line (vector) hase blue color and its frame (one pixel) the black color. Thanks!
3
votes
2answers
703 views

How/Where can I find vector data for building footprints in Texas?

I've done a lot of research on this topic over the past 8 or 9 months, but I'm a GIS newb, so I may have overlooked some possibilities for finding/extracting this data. A short list of resources I ...
3
votes
2answers
135 views

Split Lines at Intersection of Other Lines

I have two line layers (roads and contours in this example) and I would like to split the roads layer every time it crosses/intersects a feature on the contour layer. I can't seem to find a tool that ...
3
votes
1answer
193 views

Show alternating contour lines

Is it possible to show only every other counture line? And how do you do that? (Im new to QGIS Lisboa 1.8.0, but even newer to QGIS Dufour 2.0.1, but have used ArcGIS a bit a while ago, and also ...
3
votes
4answers
190 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 ...
3
votes
1answer
137 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 ...
3
votes
1answer
536 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
384 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
849 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.