A layer is a collection of information. It contains specific elements of a gis in a specific presentation method (e.g raster or vector layer). Layers can be edited separately in order to create individual toppics for a map.

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21
votes
5answers
9k views

What is difference between map layer and spatial dataset (e.g. feature class, shapefile)?

This may be very trivial question. To me they seems very similar in concept. What is the difference between feature class and feature layer?
8
votes
5answers
3k 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 ...
7
votes
1answer
978 views

Sort layers in QGIS table of contents?

When I load a bunch of layers into QGIS from PostGIS, they seem to load in reverse alphabetical order. Is there any tools or plugins that allow you to quickly sort the QGIS TOC in a different order? ...
13
votes
6answers
2k views

How to improve rendering performance of very large shapefile?

I have a polygon shapefile that has a 100MB .dbf and 500MB .shp file component. The reason it is so large is it is a landbase classification for a whole district. Everytime I am viewing the file in ...
2
votes
1answer
836 views

Create new polygon layers from postcodes latitude & longitude

First at all, I want to say that I am geocoding enthusiastic but have no formal background on GIS. I'll do my best to use the right wording and make myself clear what I am striving for. Also the only ...
1
vote
3answers
3k views

Merging Two or More Layers

I am working with three clipped layers that are shown in the TOC. I created these layers from a large watershed shape-file. However, each clipped layer includes the layer before it and only expands on ...
3
votes
2answers
2k views

Load layers only when zoom level is reached

I'm trying to load different layers based on the user zoom level with OpenLayers. I've seen some similar questions in here, but they load the layer and then hide/show it based on the zoom level. I ...
2
votes
5answers
2k views

Is there any way to extract coordinates of a road segment using QGIS?

I add my own road vector data on top of Google map using open layers plugin with QGIS. The vector layer is generated using PostgreSQL DB. Is there any way to extract coordinates of a road segment ?
2
votes
1answer
343 views

QGIS identify features button issue

Is there anyway to get the Identify Features button in QGIS to automatically select a layer and provide the information without having to highlight it first in the layers TOC? MapInfo and ArcGIS ...
5
votes
1answer
827 views

Can I change properties of several layers simultaneously?

I'm working on bulk data. I have a few hundred GeoTIFF images imported into a QGIS project, and I'd like to modify their layer properties - things like the no-data-value, transparency of certain pixel ...
3
votes
2answers
154 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
1answer
2k views

How to set up a layer control using Leaflet?

I have been working on a mapping application using Leaflet. I am using a WMS on Geoserver to get my layers, which are overlaid on a cloudmade basemap. I tried to use the layer control on my map by ...
3
votes
1answer
2k views

XYZ Layer in Open Layers has Missing Tiles

In Open Layers I'm having a missing tile problem where it generates a missing link icon and a pink background. I found several threads including this one saying to add this code ...
3
votes
1answer
247 views

List Elements or Datasets of a given Layer

I am sorry of this might sound like a noob question but I cannot find any answer from google. I used arcpy to do batch processing of Network Analyst - Make Service Area layer of thousand of stores. ...
2
votes
1answer
150 views

How to replace the legacy function “doQueries ” to AMD ESRI Javascript format?

I'm trying to understand the migration of ESRI API for javascript, from legacy to AMD. In the case of this example, how replace the fucntion doqueries????: function init() { map = new ...
2
votes
1answer
771 views

Add AutoCAD .dwg annotation file to Arcmap using python (Same as +ADD Data button)

I would like to add an AutoCad .dwg file to Arcmap using python the same way that the +ADD Data button does. I can add an Annotation layer with python but only as a feature layer not as an annotation ...
1
vote
1answer
481 views

Applying layer file not formating labels in ARCGIS 10

I'm applying layer files in ARCGIS 10 using the ApplySymbologyFromLayer_management command via a python script tool. The symbology part works fine but the lables are not formatting. It is my ...
1
vote
1answer
832 views

How to remove layers of detail from an osm file?

I want to remove some layers from the osm map of an area. It has all the details like POI, offline routing and all. But I just want the map data. How can I remove this extra layer from the map?
0
votes
1answer
238 views

How to resolve error “Handle bad layers” in QGIS?

I'm new to QGIS and have been seeing what it can do for me – seems good. I imported shape file data from a UK Ordnance Survey data file and saved the file in a new folder. It was very good, doing all ...
0
votes
1answer
2k views

How to Obtain the feature attributes from feature collection

I am able to obtain the features of the layer which is selected by the user in the Layers table and then intersected by a user defined polygon, using e.features. I was able to obtain the attribute ...