A coordinate-based data model that represents geographic features as points, lines, and polygons.
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 ...
0
votes
1answer
44 views
Different Styles Within Vector Layer
Is there any way to configure OpenLayers styling method? I have a vector layer and I would like to style the features depending on a value of a flag variables, so I can't use rules. Lets say I have ...
3
votes
1answer
74 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 ...
0
votes
2answers
35 views
add a vector point on OSM map
I have managed to show Lat and Lon
function init() {
navigator.geolocation.getCurrentPosition(function(position) {
document.getElementById('myloc').innerHTML="Latitude: " + ...
5
votes
3answers
2k 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 ...
4
votes
1answer
55 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 ...
0
votes
0answers
11 views
what is the alternative of setZoomLevel in vector based map
It is commonly used to generat map tiles at a certain scale and re-organize them for web map on pc. For example googlem map, and bing map.
Then user will use the setZoomLevel(int level) or something ...
1
vote
1answer
37 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 ...
0
votes
1answer
86 views
Drawing pie charts with vectors on OpenLayers?
Is anyone got any examples of drawing pie charts with vectors as markers on OpenLayers ?
Cheers,
4
votes
3answers
7k 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 ...
1
vote
0answers
39 views
Base station coverage analysis in QGIS
I want to find base station coverage for a instant location. I have building data. And i determine optimum coverage as 500m far away from a base station (buffer). So how can i find optimum base ...
3
votes
1answer
72 views
Are there plans for improving performance of vector files in QGIS?
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 ...
1
vote
1answer
36 views
Stamp out and transfer values from one overlayed vector layer to another
I have a vector layer with administrative boundaries and another vector layer with postal code boundaries, which are more precise/smaller entities/objects.
I now want to transmit the values of one ...
1
vote
0answers
44 views
Looking for best practice to connect multiple road vector line layers for routing (pgRouting) purposes
The Data I have:
Bridges (line layer)
Municipal_roads (line layer and does not include information in Bridges)
State_roads (line layer that doesn't include Municipal_roads or Bridges)
Question:
...
3
votes
1answer
98 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 ...
0
votes
1answer
48 views
Give Properties to a shapefile to be used by another person [duplicate]
I have bedrock geoology data. I want to classify the data so it appears with the same propeerties as it does on the suppliers website.
Is there a way i can attribute a property to a layer (in this ...
0
votes
2answers
60 views
GRASS: populating attribute table with specific values
I have a vector map that includes 100 points. These points were created using v.extract to randomly sample a larger map of 10k points. As such, the 'cat' values range from 1 to more than 10k. What ...
3
votes
1answer
94 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 ...
1
vote
1answer
114 views
How to export 2d vector graphic from Arcscene?
I need to know how to export 2d vector graphic from ArcScene so I can edit it with illustrator. I've tried changing the options when I export 2D scene as AI file or PDF file, but they always remain as ...
1
vote
1answer
76 views
Is it possible to fix a vector layer after I badly georeferenced a map? [duplicate]
Sorry in advance if I missed another question on this topic. I searched for everything I could think of, but I didn't find anything with a solution to my problem.
I am quite new to GIS tools and ...
0
votes
0answers
50 views
Reset style on select Leaflet polyline
Using Leaflet, how can I reset a polyline to it's previous color after it was selected? I have the following function that has been applied to each polyline when constructed:
function ...
0
votes
1answer
31 views
NVS Vector Stream Tool installation problem
I can't the NVS Vector Stream Tool working (version for ArcGis 10.0) in ArcGIS 10.0 SP4. I cannot find any associated toolbox. I have tried System Toolbox, My Toolbox, looking in the installation ...
4
votes
1answer
44 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 ...
22
votes
6answers
28k 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 ...
9
votes
1answer
7k 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 ...
0
votes
0answers
33 views
OpenLayers Vector Line Feature hard to select
I have a measurement control on an OpenLayers map which allows the user to (unsurprisingly) measure lines and areas on the map. They draw the line/area they want, OpenLayers does the measurements ...
1
vote
1answer
29 views
GRASS: shift point locations in a random direction
I have a vector map that contains 100 points. For each point, I would like to shift it 250 units in a random location. It's easy enough to shift all points in a specified direction using
v.edit ...
0
votes
1answer
20 views
Is it possible to update layer source in qgis
I've loaded a few shape files as layers in qgis, and I'd like to make a duplicate of the project and all associated shape files into a single directory. However, all of the layer sources are still ...
3
votes
1answer
203 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 ...
2
votes
2answers
135 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.
0
votes
1answer
79 views
Openlayers Linestring over edge of map
im trying to create a route displayer for ships. But im struggling with the edges of the map. When going from ie. 179* to 2* it displays a line across the entire map, instead of displaying it on the ...
0
votes
1answer
47 views
render kml 10mb KML file cordinates data on OSM map throws stop running script error in OpenLayer.js file
I am trying to render the kml file having 18000 line string data on OSM map using openlayer HTTP strategy.
To render OSM map i am using GeoExt.MapPanel and ExtJS 3.4 viewport.
The problem is I am ...
4
votes
0answers
73 views
Assigning costs to a road network : use raster or vector?
I have a road network in a PostGis database (db_routing). In another database (db_environment), I have some spatial features of the surrounding environment (trees as points and water bodies as ...
3
votes
1answer
452 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 ...
7
votes
5answers
504 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 ...
1
vote
2answers
1k views
Some Help to select some features from a vector layer
I have a vector layer (kml) that has some point with scientific name of plants and animals, some description of the place where the people saw them and the coordinates.
Basically the table associated ...
3
votes
1answer
206 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 ...
1
vote
1answer
132 views
v.dissolve renames the attribute table column and does not produce a dbf
When I run v.dissolve on my vector...
v.dissolve --o input=pass2@mapset1 layer=1 column=fttcp output=pass3
The dissolving appears to work but the column name in the attribute table has changed from ...
6
votes
3answers
1k 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 ...
2
votes
0answers
174 views
popular solution for display both tiles and vector data in android map app
We are planning to build a location based app like google map in android.
We have some experiences in the PC development,that's to say we have a similar javascript api like google map javascript api, ...
1
vote
1answer
82 views
How to invert polygons (or other options for exterior styling)?
I have a shapefile containing many polygons that I want to use to mask a raster. I have tried gdalwarp -cutline <shapefile> -crop_to_cutline -srcnodata -9999 -dstnodata -9999 ...
3
votes
2answers
109 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)
5
votes
3answers
268 views
How to update feature positions with clustering in OpenLayers?
I have an OpenLayers 2.12 map with a vector layer with a cluster strategy. All the static behavior is how I want it. Now I'd like to add the possibility to update the features' position. I do this ...
0
votes
0answers
27 views
Can QGIS transform a set of XY coordinates to a new set reconciled to UTM coordinates?
I have a large data set of coordinates (in meters) measured on the ground relative to a set of trails in Peru. These were generated in the 1990s with a tape measure, and there are about 3000 of them. ...
7
votes
2answers
93 views
Hashing functions for GIS data
I would like to take geometries from a vector dataset and reduce them to a hash. This hash would then be used to verify the integrity of that data and also identify identical geometries.
Do any ...
1
vote
2answers
80 views
How to create Concentric Circles in QGIS?
I'm trying to build a planning tool for center pivot irrigation system. It involves selecting a field (polygon), a center point, and then an outer circle to set the outer limits of the system. From ...
6
votes
3answers
928 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: ...
1
vote
1answer
83 views
How to convert a shapefile polygon to raster in C#
Does anybody know a way to convert a polygon (vector) in a shapefile to raster data WITHOUT using ArcGIS Explorer Desktop? Is there a way to do this 'progmatically' in C# (WPF with ArcGIS runtime ...
1
vote
1answer
91 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. ...
2
votes
0answers
66 views
Is there a way to create a catalog of vector layers in ArcGIS?
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 ...
