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

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4
votes
2answers
335 views

Vector Analysis: Determining area of county land mass without water features

Here are the layers that I have: State / Province polygon file (With Area Field) County / Ward polygon (with no area field), but all the polygons are within the state boundaries Water ways for the ...
8
votes
2answers
908 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. ...
4
votes
1answer
2k 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 ...
2
votes
1answer
477 views

polygon map overlay algorithm

There are many algorithms for binary map overlay operation in vector data format which take two layers of map and produce resultant layer i.e overlaid layer as output. I am wondering whether there are ...
6
votes
1answer
6k views

Openlayers wfs vector layer

I'm trying to add a vector layer with a wfs layer and it's not working.Can anyone point a solution? Openlayers code: var wfs = new OpenLayers.Layer.Vector( "Stavros Features", ...
7
votes
4answers
3k 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 ...
5
votes
1answer
1k views

How to draw or edit curved lines in free GIS?

I'm searching informations about drawing simple curved arrow lines into free GIS like QGIS, in this problem data geometry is CIRCULARSTRING ( a type which exists in latest postgis version) It seems ...
6
votes
1answer
4k views

How to create a point along a line given distance

I have been given a non-spatial database which contains the names of lines which I have a shapefile for. The database also has names of points and the distance of each point from the origin along the ...
2
votes
0answers
466 views

Creating a sidewalk map for a walkability survey

If I wanted to do my own walkability survey of my city, what tools could I use? I have map data from OpenStreetMap, but I have to consider that streets have two sides (which aren't always accessible ...
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 ...
15
votes
2answers
7k 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 ...
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
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 ...
1
vote
1answer
210 views

Any freely available vector data in cylindrical projection?

I'm trying to develop an application in PHP to plot various points in Europe from a database, and serve them dynamically on a map. I think this should be relatively straightforward when using a map ...
2
votes
1answer
771 views

How to clean vector segment intersect errors in GRASS

I'm using GRASS to process a vector map. When I export back to .SHP and do a 'Check Geometry Validity' in Quantum GIS it lists several errors of this type... 3,segments 199 and 203 of line 0 ...
2
votes
3answers
1k views

Convert Arcgis Rest to OpenLayers Vector

i am working with openlayers and esri rest services... in my api due to esriGeometryPolygon for all city , rendering map is taking lots of time ..there for i dont take a good result.. first of all is ...
14
votes
1answer
23k 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 ...
24
votes
3answers
24k 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 ...
4
votes
2answers
4k views

Reclass for vector data in ArcGIS

I've got a vector dataset (in fact, OS MasterMap data) and I want to set the value of a certain field based on the value of another field. For example: Field1 Field2 Building 20 Grass ...
12
votes
6answers
5k 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 ...
4
votes
1answer
4k 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 ...
6
votes
3answers
6k views

Finding nearest raster cell value based on vector point?

I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
3
votes
2answers
122 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
192 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
3k 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
0answers
1k views

How to get turn angle, line orientation and line length in ArcMap 9.3.1?

I am mapping and analysing animal movements using arcgis 9.3.1 along with Hawthorne Beyer's GME, and am trying to utilise the correlated random walk commands, but in order to do this I need to find ...
3
votes
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 ...
8
votes
3answers
11k 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 ...
3
votes
3answers
775 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 ...
4
votes
5answers
679 views

How to save a raster and vector into a single PNG file in GRASS?

I am trying to save a raster and vector into a PNG file. The vector is overlayed on top of the raster map. I was only able to save the raster file into a png using r.out.png but without the vector.
4
votes
1answer
773 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: ...
33
votes
5answers
71k 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 ...
4
votes
3answers
11k 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 ...
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 ...
7
votes
3answers
3k views

Creating a raster surface of overlaps from vector polygon shapefiles?

Basically what I'm trying to do (in ArcGIS 10) is to compare three vector files in order to create a 'comparison' raster layer. I tried using Data Comparison (under Data Management tools) but it ...
10
votes
1answer
447 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 ...
5
votes
2answers
579 views

Distribute points respect to features using Quantum Gis

I want to know if there is any tool to make points with respect to selected features in a theme? Using: vector, investigating tools, regular points you can do it but not with respect to a selected ...
0
votes
1answer
127 views

How to create a new table for a vector file?

I will use v.db.connect but i want to use a new table, and not an existing table to connect it to. What is the GRASS script for it? Thanks!
1
vote
1answer
193 views

Why is the geonames not loading?

I want to import a geonames file. I downloaded the geonames .txt file from http://download.geonames.org/export/dump/ I used: v.in.geonames input=PH.txt output=ph but it displayed ...
1
vote
1answer
940 views

How to select a raster file that is under a polygon in a vector file?

I am using: v.db.select map=PHL_adm1 where=NAME_1='Bulacan' My vector map is over the raster map. I want to select the part of the raster map under the polygon(NAME_1='Bulacan') of a vector. Is it ...
1
vote
1answer
2k views

How to combine a vector and a raster file?

I want to combine a raster and a vector file. After combining, can I query on the resulting map to obtain a specific area? How?
4
votes
1answer
398 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
2answers
917 views

Calculate spacing of polylines along transects in ArcGIS

I have a shapefile with a number of roughly parallel lines in it, and I want to calculate the spacing between these lines using a number of transects across the map. How should I go about this? I ...
2
votes
2answers
574 views

How to query data from a vector map (shapefile)?

We want to obtain the specific place of the boundaries of a shapefile. We want to be able to get the points of each polygon corresponding to a specific place in order to use these data in an ...
3
votes
2answers
2k 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), ...
4
votes
4answers
6k views

Merge overlapping lines in ArcGIS

I have a polyline shapefile containing a number of lines, some of which overlap. By overlap, I mean that they follow exactly the same path for some of their route, but also have bits that are not ...
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
4answers
3k 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 ...
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 ...
5
votes
3answers
7k views

Free Mercator, Vector Maps

Are there any free, vector, mercator projection maps available online? I'm not wanting satellite imagery, but more a stylized map along the lines of this: However, I need it to be vector-based such ...