Questions tagged [layers]

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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62
votes
3answers
86k views

Layers with same coordinate system should align/overlap in ArcMap but do not?

I put 4 different layers into my ArcMap document, but only one of them will show up on the map! I should be seeing the other 3 layers as well. When I do a Zoom to layer, I can see one layer, but I ...
35
votes
8answers
39k views

Georeferencing vector layer with control points using QGIS?

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 ...
37
votes
6answers
38k views

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

What is the difference between a feature class and a feature layer? To me they seem very similar in concept.
20
votes
2answers
35k views

Adding shapefile or feature class as layer in ArcGIS Desktop using Python/ArcPy?

I am trying to automate various tasks in ArcGIS Desktop (using ArcMap generally) with Python, and I keep needing a way to add a shapefile to the current map. (And then do stuff to it, but that's ...
12
votes
1answer
5k 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? ...
29
votes
3answers
6k views

Organization and tidiness of multiple copies of layers? [closed]

Back in the days when I was in the university I had a "Organization and tidiness" problem – I was unorganized and kept my layers in different folders without distinct names and hence had multiple ...
13
votes
1answer
11k views

Use python to add layers to TOC

I've been battling with adding layers to the TOC for some time now. I have managed to single layers added but need to loop through a folder and add all layers. Shapefiles I cannot get to add at all. ...
6
votes
2answers
7k views

Adding feature class to Map in CURRENT project using ArcPy in ArcGIS Pro?

I want to add a feature class within a Geodatabase to a map in ArcGIS Pro (1.4.1) using arcpy. I am converting some python code from ArcGIS Desktop to ArcGIS Pro. This issue is very similar to: ...
38
votes
5answers
23k views

Change style 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 ...
12
votes
1answer
16k views

How to add feature class to MXD with ArcPy (Python)? [duplicate]

I am using ArcGIS 10.1 and I am trying to add a feature class that I create to an MXD, so that I can join to it. This all needs to be done using Python. Is this possible?
19
votes
3answers
25k views

How to perform a true GIS clip of polygons layer using a polygon layer in R?

I would like to do a true GIS Clip in R of soils polygons using a series of single boundary polygons, but I cannot find an R function to properly do it. It should work just like the clip function in ...
32
votes
4answers
23k views

Iterating 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 ...
17
votes
5answers
14k views

Getting path of project, or layer file in PyQGIS?

I am generating new raster files from vector layers on a project. I would like to save them in the same directory as the project or layer files. How do I find this path using PyQGIS?
11
votes
2answers
15k views

Changing data source path involving feature dataset in *.lyr files using ArcPy?

How can one change the source data paths for every layer file in folder X using arcpy? I've followed Updating and fixing data sources with arcpy.mapping as best I can, yet all I get is an unhelpful ...
9
votes
2answers
3k views

Symbols above labels in map QGIS

I didn't find any answer to this question. In this post it is said that labels are by default on top of everything else: How to place labels under a vector layer?. But it was for 2.2, and years went ...
12
votes
8answers
51k views

How to export/save a layer composition to GeoTiff?

I want to export/save a QGIS composition of raster/vector layers to a GEOTIFF or ECW raster with high resolution (20 000 * 20 000 Pixel).
4
votes
2answers
3k views

Changing color of symbol in UniqueValuesSymbology object using ArcPy?

I have an template mxd I reference with several pre-defined layers. The only variable I need to modify is the color of certain symbols in the layer. I have tried to modify and dig around the Symbology ...
20
votes
7answers
16k views

How to improve rendering performance of a 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 that it is classified as a landbase for a whole district. Everytime I view the file in ...
16
votes
3answers
7k views

Using ArcPy to get layer symbology?

Since ArcGIS 10 comes with the ArcPy package, I'm wondering it is possible to use ArcPy functions to get Symbology (i.e color, width...) of a layer?
2
votes
5answers
9k 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 Maps using the OpenLayers plugin with QGIS. The vector layer is generated using a PostgreSQL DB. Is there any way to extract coordinates of a road ...
7
votes
2answers
11k views

Using Google Maps as layer in ArcMap?

Can I use Google Maps as a layer in ArcMap? Is it possible?
10
votes
2answers
13k views

How does Zonal Statistics work exactly?

I'm a bit confused on how the zonal statistics tools work in QGIS (either the 'Zonal Statistics' tool under the Raster tools from the QGIS geoalgorithms toolbox or the 'Raster statistics from polygons'...
13
votes
5answers
21k views

Removing feature layer using ArcPy script?

I have an ArcPy based script where I'm trying to intersect two layers where one layer must have its centroid in the other layer. Since I need to know that one layer (feature_layer below) includes ...
5
votes
3answers
7k views

Setting layer visibility in QGIS Python API?

Im having a problem toggling the visibility of map layers in pyqgis (2.4). I have a simple interface, just the map canvas, no legend, and basically a radio button that toggles between two raster ...
11
votes
3answers
25k views

Getting extent of layer in QGIS?

Is there a way to get the extent (bbox) of a vector layer in QGIS? I see that I can update the extent, but I am looking for the actually coordinates of the extent.
8
votes
1answer
7k views

what dictates the drawing order of overlapping features with in the same layer/feature class in ArcGIS?

I know that in ArcGIS drawing order is controlled by layers, and if I want to make some features be drawn on top of other features I can use definition queries to separate them into different layers ...
4
votes
2answers
4k views

Creating sub sections (groups) of layers in QGIS?

I am working on a project regarding Fish species and fishing methods with many layers. This creates confusion. I would like to create layer sub sections (groups) like the following: Fish Species ...
11
votes
3answers
2k views

How to ignore “handle bad layers” in QGIS?

I have a QGIS (2.14.3-Essen) project that I use both at work and at home. I keep all but two layers with the project. The two remaining layers are very large - a DEM and hillshade totaling more than ...
8
votes
2answers
7k views

Activating layer by its name in PyQGIS

I'm writing a script that requires the attributes of different layers to work, and I would like to know how to call a layer that is not the currently active one and get its features. For example, I ...
18
votes
2answers
12k views

Making QGIS layer update from changed data source

I'm trying to get layers to update automatically when their data source changes. I'm using R to write a shapefile with an attribute, and colouring according to that attribute in QGIS. I want to write ...
5
votes
1answer
4k views

Exporting each layer in map to separate image using ArcPy?

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 ...
9
votes
2answers
7k views

Turning on labels of layer using ArcPy?

I am unable to turn on the labels within my Python script: import arcpy mxd = arcpy.mapping.MapDocument(r"Mypathhere") #Map document reference layer = arcpy.mapping.ListLayers(mxd, "Layername")[0] #...
6
votes
2answers
5k views

QGIS split vector layer gives me GPKG files but I need shp files

QGIS 3.6.0 I am new to QGIS software and not very technical on its deep workings. I am trying to split a .shp file using split vector layer. I need .shp file outputs but it auto creates .gpkg files. ...
4
votes
2answers
1k views

CSV text files loading error / crash in QGIS 2.18.8

I got a problem when I try to load tab-separated text files in the "Create a layer from the delimited text file" tab (that one with de comma symbol). After normally selecting the X and Y fields and ...
1
vote
1answer
5k 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 ...
32
votes
3answers
17k views

How to refer to another layer in the field calculator?

Is there a way to select an attribute from a polygon layer and insert the value into a virtual field of a point layer using "within" in the field calculator? CASE WHEN within($geometry, ...
20
votes
5answers
25k views

Using layer loadstart & loadend events in OpenLayers 3?

OpenLayers 2 has these layer events "loadstart & loadend." What is equivalent to them in OpenLayers 3? While a vector layer loads and is rendered, I need to show a loading icon.
13
votes
2answers
34k 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 button....
25
votes
7answers
48k views

Changing data source for all layers in MXD?

I have an MXD. It connects to about 30 layers in one of our SDE databases. I want to change the SDE database they connect to. Is there a way to do this without having to right-click every layer ...
9
votes
3answers
12k 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 attributes....
11
votes
3answers
19k views

Setting Definition Query on ArcPy layer from shapefile for ArcMap

I am trying to determine options to set a layer definition query using ArcPy. I know that it is possible when using arcpy.mapping.ListLayers(). However, in this scenario I am loading in ...
3
votes
1answer
13k views

Accessing secure Geoserver layer with username password

I've created Users, Groups and Roles in Geoserver. And I set the user roles for my workspace. user1 can read user2 can write And I want to access my layers as anonymous like this: http:localhost:...
2
votes
1answer
3k 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 ...
6
votes
6answers
3k views

How to create multiple QGIS layers from multiple text files?

I have a few hundred txt files (each representing a line of a river bed profile) that I need to load as (point-) layers in QGIS. Partial example: 4504764.8331;5374251.3024;397.8871;2 4504764.7761;...
4
votes
2answers
9k views

Defining which layer (overlay) is displayed on Leaflet map?

I have 7 layers overlay on a base map, i need to define which layer is selected (active,displayed,shown) on the map. var overlays = { "AL HOUDA Espaces_Verts": alhouda6_layer, "...
4
votes
1answer
604 views

GetFeatureCount gives same result after deleting a feature

This is my code: num1 = layer.GetFeatureCount() layer.DeleteFeature(1) layer.SyncToDisk() num2 = layer.GetFeatureCount() print num1 print num2 For some reason, num1 and num2 are the same number. Why?...
3
votes
1answer
2k 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 ...
9
votes
1answer
8k views

Delete layer from ArcMap using Python

Problem: I'm trying to loop through all my layers looking for layer named "CADAnnotation". If the layer exists then remove the layer from the mxd Notes: Running from Stand-Alone script (ie. NOT ...
7
votes
1answer
2k views

Is it possible to set different scale dependent visibility for one layer classifications?

I'm working on a sewer and water network, so I need to set different scale visibility for primary, secondary and tertiary network.
7
votes
2answers
8k views

How to get layer type in OpenLayers 3?

I would like to iterate through all of the added layers in an ol.Map instance and only select the vector layers. So far I could get the individual layers with the a property of the resulting object of ...

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