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
12k 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?
14
votes
6answers
3k 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 ...
9
votes
7answers
5k 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 ...
8
votes
2answers
3k views

How can I iterate over map layers in QGIS python

I'm having trouble figuring out how to iterate over map layers. I can access the currently highlighted layer in the table of contents via iface.activeLayer() but I want my code to operate on all ...
7
votes
2answers
4k views

Leaflet: How to move the layer-control menu?

This might be a silly question, but I could not find a documented way to achieve this. I'd like to freely position the layer-control menu, probably to the top left near the default zoom-in/out ...
7
votes
1answer
2k 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? ...
6
votes
4answers
530 views

Is there a universal map/ layer format?

Just wondering if there is a universal map format that all GIS software can read. ie to quickly share layers with all our partner agencies which have different GIS Software, rather than have to ...
6
votes
2answers
1k views

How to copy a group of layers between QGIS projects?

In ArcGIS I am used to being able to have a couple of MXD documents open and copy-paste groups of layers from one MXD's table of contents to another. This can save a LOT of time ensuring consistent ...
6
votes
2answers
1k views

Can QGIS preserve layers when exporting a PDF? [duplicate]

I saw this posted about a year ago (Can QGIS preserve layers when exporting to PDF?) but figured it was worth asking again -- is this possible? My usual workflow with ArcGIS is to export to AI then ...
6
votes
1answer
118 views

Can I save an ArcGIS GeoPDF with all layers turned off, which can then be turned on individually in a pdf viewer?

I am working on an mxd that has many individual point layers (displaying species locations). To make life easy for my stakeholders, I'd like to export to a GeoPdf so that all of these point layers are ...
6
votes
1answer
635 views

How to add layer with ArcPy and retain feature class metadata (like Credits) in layer properties?

I have multiple feature classes in a geodatabase, each feature class has metadata including a Description, Credits, and other information. If I use the 'Add Data' button in ArcMap 10.1 to add one of ...
6
votes
1answer
175 views

Load third-party APIs only when the corresponding map layer is requested?

OpenLayers allows multiple map layers to be hosted on a common platform. If the map application supports a wide variety of maps, say from Google, Yahoo and Microsoft, I find that upon initialization, ...
6
votes
3answers
225 views

Automating an ArcGIS Project that is a display of map

I'm relatively new to GIS and looking to automate a project. I have my 'base map' created in ArcGIS, but now need to create several hundred more so looking for an automated method to accomplish this. ...
5
votes
1answer
1k 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 ...
5
votes
3answers
8k views

Change Icon of Single Vector Feature in Layer

Currently I am trying to change the icon of a particular feature of a vector layer that the user is focusing on. I add each feature to the map like so: var point = new ...
5
votes
1answer
535 views

MXD Performance - number of layers vs number of datasets

My mxd currently has 5 buildings layers accessing 5 different buildings datasets (one for each of 5 counties). Most often there would only be a single county's buildings in the current view, if that ...
5
votes
1answer
1k views

How do you symbolize a feature class layer in ArcMap 10 based on one attribute's value and then another attribute's value?

I currently have a point feature class that has a couple of attributes that I want to use to symbolize its layer. One of the attributes is called ExceedsTolerance, which either has "Y" or "N" for its ...
5
votes
2answers
2k views

Create multiple vector layers by reading a GeoJSON file once in OpenLayers

I am a begginner to OpenLayers, and my question is about making things more efficient. My work is about displaying time-dependent weather elements on several point locations on the map. All these ...
5
votes
3answers
2k views

How can I set the base layer of map before initialization?

I have been using map.setBaseLayer(layer); to switch to my preferred map layer, using the localStorage variable layer that is stored in my web browser, upon initialization of the map. But I realize ...
5
votes
1answer
143 views

How to convert PostGis Table (Grid data) to Continuous field using Qgis?

I'd like to transform my Gridded Layer (generated form a PostGIS table of points) to a continuous and colored layer. How could I do this with Qgis or any other program? Many thanks and best regards, ...
5
votes
1answer
1k views

Export each layer in map to a separate image

I have a mxd file with multiple layers I have to export to PNG/JPG. I would like to create a script which turns on layers one at the time before they are exported. So far I have come up with the ...
5
votes
0answers
47 views

What prior art can be cited to refute Apple's claim to have invented Interactive Map? [closed]

In U.S. Patent Application 20130339891 Apple Inc. claims "An interactive capability enables a user to dynamically adjust the content of an electronic map" as well as "Geospatial applications can be ...
4
votes
3answers
6k views

How to get the layer name?

I am using OpenLayers, Geoserver 2.1 CQL language. The problem is that I do not know how to address the layer. I am trying to call a function like this: var createWmsLayer = function(name, url, ...
4
votes
4answers
1k views

How to get vector data from OSM to use in QGIS?

How do I get data from OpenStreetMap which I can then edit in QGIS layer by layer? What is the best OSM output and what / how do I get to a suitable input for QGIS? OR...is there another appraach to ...
4
votes
2answers
119 views

Layer just for annotations

Im relatively new to QGIS and would like to know whether or not I can save my form annotations to a layer so I can turn them on or off.
4
votes
1answer
945 views

What is Python equivalent of ModelBuilder's Iterate Feature Selection?

My data consists of two featureclasses: Points = points representing trees Polygons = Polygons representing % canopy area by area. Each polygon in the FC has a % canopy measurement in the ...
4
votes
2answers
376 views

Is there easy way to get layers names from WMS server?

I've been looking for information on how to get layers names from certain WMS servers, but I didn't find any. E.g. I have this server: http://sdi.geoportal.gov.pl/wms_prg/wmservice.aspx and I want to ...
4
votes
1answer
1k views

OGR and DXF files: Is it possible to handle layer names? (only “entities”)

I'm using Python and OGR to extract the layers of a DXF file and convert them into SHP. I began with: import ogr, os, sys driver = ogr.GetDriverByName('DXF') datasource = driver.Open('test1.dxf', 0) ...
4
votes
1answer
131 views

Is it possible to store a default symbology layer in an arcpy add-in?

Since arcpy is limited in how symbology can be manipulated, I was curious to know if a symbology layer can be stored in an arcpy add-in. Does anyone know if it is possible to store a .lyr file, or ...
4
votes
1answer
544 views

Extracting donut holes as separate layer in QGIS

Does anyone know how I can extract the holes in a polygon layer as a separate layer in Quantum GIS? An example could be a country with a number of lakes cut out of the polygon - I need the lakes. I ...
4
votes
1answer
62 views

QGIS 2 bold Layer names?

I am currently working with QGIS 2.0 in an Ubuntu environment. I have a quite large project with many different layers and layer-groups. By default the layernames are in bold fonts and the groups are ...
4
votes
2answers
140 views

GIS projection for non-geographic data

I am working on two different types of data. One is related to mapping of Genome structure and another is creating a layout of the inventories inside Internet Data Center. What I am confused about is ...
4
votes
4answers
403 views

Why does the layer list context menu not open anymore?

I cannot access layers properties (i.e. change color, filter by query, anything). The mouse right click doesn't do anything. Is there a way restoring qgis to default? Ubuntu 12.04, QGIS 1.8
4
votes
1answer
48 views

Summarizing different (local) shapefiles/sources into one centralized database using ArcGIS for Desktop?

Using ArcMap/ArcCatalog 10.2, is there a way, to summarize a huge number of widely spread shapefiles/sources (different servers, different hard drives etc.) into one centralized database, in order to ...
4
votes
1answer
3k views

How do I add my own map layers to Leaflet

I have a Leaflet map and want to add two of my own small polygon layers (currently in shapefile format, but they could be converted to GeoJSON). Can this be done without a mapserver to publish them ...
4
votes
1answer
67 views

Removing some bands or layers from a tiff using gdal

I have been working on a multiband raster image. It is a pix image. I need to just work on the 26 bands that are raster files and not the 4 bitmaps that are are also included in the pix image. I could ...
4
votes
1answer
198 views

How can I modify layer order with the QGIS python API [duplicate]

Typically, after a new_layer = addRasterLayer(...) that inserts new_layer before the active layer, I'd like to move it to the top of the table of contents. How to do it? I use an existing QGIS ...
3
votes
2answers
621 views

How display many layers from Geoserver in one map?

1) I publish 4 layers in Geoserver (planet_osm_line, planet_osm_point, planet_osm_polygon, planet_osm_roads). 2) Then I add styles (from sld styles) to the Geoserver. 3) Then I set this styles in my ...
3
votes
1answer
349 views

What open-source web mapping solution I need to use for this situation?

I will try to explain what I need to do. I have about thirty KML polygons. I need to put them on some satellite map. On the top of these layers (KMLs, satellite) there must go layer with roads. I ...
3
votes
2answers
62 views

Where to look for oceanographical/environmental data for the Arctic (Baffin Bay/Davis Strait area)

I am looking for oceanographical/environmental variables that are available for Baffin Bay/Davis Strait area over the time period of 1995-2011, however, I am not familiar with ...
3
votes
2answers
164 views

Why might layer appear not to turn off in ArcMap?

I was called over to try and fix an issue with a coworkers ArcGIS software (ArcView 9.3.1 SP1, Windows 7) and couldn't fix it. When a certain layer is turned off in the table of contents it never ...
3
votes
1answer
36 views

How to change the color of vector layer of QGIS in api?

I'm using QGIS-2.4.0 api to develop app in C++. When I add a vector layer to the app, the vector map's color would be random. I used QgsFeatureRendererV2 to get the geometry type of the layer, my ...
3
votes
1answer
104 views

Using Python Add-In to delete/remove ArcMap layers that are turned off?

I have made a python addin button which removes layers that are turned off in an MXD. The strange thing is that I get different results depending on whether I run the python commands in the python ...
3
votes
1answer
225 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
3answers
474 views

What Is The Ideal Workflow To Map (British) Postcode Territories

I'm looking for the best workflow for mapping postcodes and calculated territories, but being relatively new to mapping I'm struggling on a few details and also the best practices for displaying these ...
3
votes
1answer
1k views

How to add a layer file to an ArcGIS map document programmatically?

I want to create a feature layer from a layer (.lyr) file and add it to my ArcGIS map document programmatically. I am using C# and ArcGIS. I have a layer file and a shapefile.
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
68 views

Change projections depending on the zoom level

Is it possible in ArcGis (from a technology/performance/… point of view) to switch projections depending on the zoom level? For example, Is it possible when zooming at some extent to the poles, my ...
3
votes
1answer
72 views

Hotkey in ArcGIS for Desktop to delete layer from Table of Contents?

I'm using ArcGIS 10.2 for Desktop and wish to remove/delete a layer from the Table of Contents. I cannot find such hotkey. I have tried the DELETE button but that does not do it. Also such hotkey is ...
3
votes
1answer
95 views

Is there a way to know if an error occurred while loading a WMS layer, in OpenLayers 2?

First of all, I already asked this question in stackoverflow. I don't want to spam by asking again here. But I think the question fits better in gis.stackexchange. I am sorry for the replication. Feel ...