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

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58
votes
7answers
2k views

Are there any attempts to replace the shapefile?

Recently I've been spending a lot of time converting perfectly good field names like "Percent of citizens age 25 and over with a bachelor's degree or higher" into things like "edbchogtr" to meet the ...
49
votes
8answers
10k views

How to create Vector Polygons at the same amazing speeds GISCloud is able to render them?

EDIT (outlining new bounty added): I have added the largest bounty possible to this question in hope of getting a very detailed answer. Your solution should outline a step-by-step guide utilizing open ...
42
votes
6answers
92k views

What are Raster and Vector data in GIS and when to use?

What are raster and vector data in the GIS context? In general terms what applications, processes, or analysis are each suited for? (And not suited for!) In answering someone's question today, I ...
41
votes
5answers
13k views

Self-hosting Mapbox vector tiles

As presented in a talk at FOSS4G Mapbox Studio allows to create Mapbox vector tiles and export them as a .mbtiles file. The mapbox-gl.js library can be used to dynamically style and render Mapbox ...
34
votes
4answers
33k views

How to clip a raster with vector boundaries?

I am using QGIS. I would like to clip a raster precipitation layer using an admin boundary layer that is vector data. However the geoprocessing tools seem to be usable only for vector data. How can ...
24
votes
7answers
10k views

Nearest neighbor between point layer and line layer?

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...
23
votes
4answers
33k 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 ...
19
votes
3answers
816 views

How can we protect GIS data?

I have found a very interesting paper here related to this topic. I just want to have views/ideas from other professional about how we can protect GIS data using Cryptography or Digital Watermarking? ...
18
votes
1answer
300 views

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS?

Is it possible to generate a boustrophedon pattern which fill a vector Region with GRASS? I have a vector region in GRASS. And I would like to generate a vector (a polyline) being the bostrophedon ...
17
votes
2answers
10k views

How to Import SVG into GIS?

I have a PDF file, with a Map as a vector graphic. I want to get this into GIS. (I use ESRI's ArcGIS, but any FOSS solution is also fine). I know that it is not possible to directly get the PDF into ...
16
votes
1answer
29k views

Programmatically creating a vector feature in OpenLayers

I want to create a vector feature, programmatically, on my map. It's supposed to be in the A4-paperformat, for showing a sort of print preview. I've created a control for handling this, but now I'm ...
16
votes
3answers
2k views

What is the wire format for Google's new vector map tiles?

Google recently released new vector cartography for their mobile maps. I'm curious if anyone here has any insight into the wire format they use for transmission? I've experimented with a few formats ...
15
votes
4answers
31k views

How to convert a vector layer to raster?

In qgis in the raster menu there is an item "convert vector to raster". This behaves strangely - I do not understand how it is supposed to work. I can select a vector file, an attribute and an ...
15
votes
1answer
11k views

Merging adjacent polygons in shapefile that has been split at tile boundaries?

I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile. This is ...
15
votes
2answers
392 views

Toward a protocol for encoding vector data as image

This is a follow up to this question: How to create Vector Polygons at the same amazing speeds GISCloud is able to render them? In his answer, Yagi outlines a rationale for encoding geographic ...
15
votes
4answers
2k views

Rubber sheeting in GRASS or QGIS

We are in the process of getting our property boundaries corrected and a side effect of this is that we need to move any assets that have been drawn relative to the property boundaries, so they are ...
14
votes
3answers
11k views

How to move vectors to specified coordinates in QGIS?

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000). How should I do it? Preferably using QGIS.
14
votes
4answers
41k views

Extract Raster Value into Polygon Attribute

I have Raster Data for a State which has Elevation Data in its pixels. I also have Vector layer which has the 300 divisions of State. what I need is, I want to get the average elevation value of ...
14
votes
8answers
12k views

How to georeference a vector layer with control points?

I have a non-georeferenced vector layer that I need to be georeferenced. With raster layers the task is easy and straightforward, but I have no idea what should I do with my vector layer. I have a few ...
14
votes
2answers
430 views

Is there any open-source object-oriented GIS?

Most GIS are layer based. But I am looking for open-source object-oriented GIS. Is there any out there? By object-oriented I mean logical data model for vector GIS. Here's explanation of my ...
14
votes
6answers
7k views

Converting GeoPDF to vector format like CAD or shapefile?

I want to convert a GeoPDF that has vectors entity in it to a vector format and preserve the real coordinates of these vectors. The GeoPDF has been exported from ArcMap and has layers in it. I have ...
13
votes
5answers
11k views

Libraries to render vector-based maps in the browser

Is there a open source JavaScript library like leaflet or openlayer which can be used in a web or mobile application and loads vector-based maps instead of images? I only need the road information and ...
13
votes
3answers
7k views

How to find and merge duplicate points?

I have two point shapefiles: Red and Blue. Each point shapefile has a z value which represents a radius (i.e. represented as buffers in the example). A duplicate point is defined as a point that ...
13
votes
1answer
3k views

How to access feature classes in file geodatabases with Python and GDAL?

I am trying to access a vector dataset in a ESRI File Geodatabase using Python + GDAL. I have successfully compiled GDAL with the file geodatabase API. The FileGDB driver is working correctly since ...
11
votes
4answers
488 views

How to generalize coastlines?

I have a large set of data points that essentially represent the coastline of the world. I don't know the exact resolution but I'd say it's in the neighbourhood of 5-10m. Imagine a set of points ...
11
votes
2answers
2k views

Moving points onto lines (~neighborhood)

I do have two vector layer, of which one is a point layer based on "events" by remote sensing and the second one is a line layer from local research. In my case these are earthquakes and tectonic ...
11
votes
1answer
480 views

Spatial operators in R?

How can I do spatial selections or filters in R? I can do this in PostGIS using (e.g.): SELECT * FROM mypoint, mypoly WHERE ST_Within(mypoint.geom, mypoly.geom); and it is similarly a piece of cake ...
11
votes
2answers
1k views

Tiling Vector data without losing geometrical and topological information

I am trying to figure out a way to sub-divide a vector based map into smaller blocks. I can tile the map based on different strategies such as q-tree. However, it is unavoidable to cut some polylines ...
11
votes
1answer
521 views

SEXTANTE toolbox - GRASS error

I am trying to use the SEXTANTE module GRASS (and SAGA) for vector analysis but whatever function I use I always get the same error:"Could not load layer: G:/closest.shp Check the SEXTANTE log to look ...
10
votes
3answers
961 views

In what coordinate systems do true circles appear round?

Please excuse what is probably an obvious question from a relative newB to GIS -- this seems like it should be a snap. I've been developing in Gmaps for awhile and am switching to OpenLayers but am ...
10
votes
2answers
6k views

How can I programatically create and add features to a memory layer in QGIS 1.9?

I had a working plugin in QGIS 1.8 which read data from an MSAccess database and added it to a series of memory layers. There is some processing involved in the interim so I don't think simply using ...
10
votes
2answers
715 views

How do I describe a special relationship between connected edges?

Consider this simple situation where three edges connect at a node: I’d like to write a succinct and clear description of the relationship between A and B in such a way that differentiates it from ...
10
votes
1answer
623 views

What is the best way to represent bridges using a point vector layer in QGIS?

I'm working on a hiking/biking maps of trails in the woods which sometimes have bridges that need to be shown on the map. I'm trying to figure out the best way to capture and represent them using QGIS ...
9
votes
2answers
445 views

Creating an “average” polygon

I found this thread in the old ESRI forums with the same type of problem I am facing today. The solution to the problem is explained in little detail and since I am not an expert, I was wondering if ...
9
votes
2answers
2k views

What's the best way to display thousands of polygons in Openlayers?

I am trying to create an Openlayers map that will display thousands of polygons. And when the user clicks on each, I want some of the metadata to display. Working with this large of a dataset seems ...
9
votes
1answer
2k views

Why do vectors disappears when zooming in?

I have imported a .gpx file into qgis and separated the track waypoints using Vector > GPS > GPS tools. When viewing at full extent I can see the original track and component waypoints. However when ...
8
votes
4answers
6k views

How to split a vector in equal smaller parts in QGIS or similar?

i want to divide a shapefile with many tiles into a lot of smaller tiles. I am searching for a smart solution, because manual edits are out of questions Anyone can help or know a nice function?
8
votes
3answers
4k views

How to create a new Spatialite database in QGIS

I've been trying to create a new spatialite database within QGIS 1.8 (SpatiaLite Version 3.0.1; QSpatialite 6.0.3) and keep getting this error: "The SQL query seems to be invalid. no such table: ...
8
votes
3answers
14k views

converting kml into a vector graphic… and back

Is there a simple means to convert, say, an svg or other vector image format file to KML and vise versa? There are incredibly powerful vector editing tools which attempt to replicate the way reality ...
8
votes
1answer
105k 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 ...
8
votes
2answers
8k views

Rotating a vector layer in QGIS with qgsAffine (or other method)?

I would like to rotate a set of vector points in QGIS an arbitrary number of degrees around a central point (or arbitrary point). This is similar to a recent question about creating a regular grid; ...
8
votes
2answers
1k views

How to convert a vector boundary to a raster map?

I need to output a PNG file of a raster map overlayed with boundaries present in a vector map. The problem is, the r.out.png script only exports a raster map. My boundaries are in a vector format. ...
8
votes
3answers
1k 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 ...
8
votes
2answers
1k 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 ...
7
votes
4answers
3k 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 ...
7
votes
4answers
16k views

Customizing Popups in Openlayers

Is it possible to customize the shape of popups in OpenLayers? For example, I am creating a pop-up using the following approach: var popup = new OpenLayers.Popup.FramedCloud( "popup", ...
7
votes
4answers
4k views

How to identify and eliminate overlaying polygons in Quantum GIS?

I have a shapefile with polygons and now, not sure why, most of the polygons became duplicated and overlaid, i.e. when i click to selected one, i get two selected... How do i identify those polygons ...
7
votes
4answers
673 views

Comparing 2 vector files

I'm looking for a tool which compares two vector files (eg shapefiles). Eg 2 versions of a river network. Quite a lot of the records are equal, but some are different. A possible output would be eg a ...
7
votes
3answers
681 views

How to get a list of adjacent lots to a road in ArcMAP and PostGIS/QGIS?

In the following map, I have: A line / road layer A parcel / lot layer The Task: Find and count the list of lots adjacent to the road with their types (parcel_type is a field in the parcel ...
7
votes
2answers
9k views

How to clip a vector feature to the extent of an existing raster dataset using arcpy

I have a clipped raster dataset with polylines (from the contour tool) overlayed (see attached). I am trying to clip the polylines to the extent of the raster dataset, which seems simple enough, but ...