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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61
votes
3answers
76k 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 ...
29
votes
8answers
30k 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
35k 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
32k 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 ...
6
votes
2answers
12k views

Nearest distance between point layer and line layer, QGIS

I have two layers , line and point layer. I need to make a line layer which connects all points to nearest line features? Did someone make a plugin for qgis? This is very important tool which missing ...
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? ...
28
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. ...
30
votes
5answers
16k 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
14k 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?
4
votes
2answers
3k 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: ...
16
votes
2answers
17k 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 ...
11
votes
2answers
14k 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 ...
10
votes
7answers
45k 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
6answers
15k 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
6k 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
8k 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
2k 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 ...
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?
13
votes
5answers
19k 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 ...
8
votes
1answer
6k 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
3k 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 ...
4
votes
3answers
5k 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
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 ...
10
votes
2answers
9k 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'...
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 ...
10
votes
3answers
21k 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.
5
votes
3answers
1k 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
951 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
4k 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 ...
26
votes
3answers
10k 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, ...
30
votes
4answers
20k 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 ...
10
votes
2answers
26k 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....
18
votes
5answers
21k 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.
8
votes
3answers
11k 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....
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 ...
13
votes
4answers
10k 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?
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 ...
13
votes
2answers
8k views

Make a Qgis layer update from a 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 ...
9
votes
1answer
7k 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 ...
8
votes
2answers
6k 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
1answer
4k views

How to load multiple vector layers into QGIS' map canvas using python scripting?

I am trying to write a standalone script in python to create a QGIS map canvas. The vector layers I am attempting to load are Shapefiles. Currently, I am able to load each vector layer, add them to ...
5
votes
1answer
3k views

Can I Turn Off or Remove Map Layers in QGIS Print Composer

The title pretty much says it all. I have a base map in QGIS that I am using with several Print Composers. In one of the Print Composers, I don't want one of the layers to show up. Is there any way ...
4
votes
2answers
10k views

Changing data source of layers with ArcPy?

How do I change the data source of all layers in a map document using ArcPy and Python?
3
votes
1answer
2k views

Standalone Python script to split a polyline with a point layer

I have a polyline layer and a layer of points that are on top of the polylines. I do not have the ArcGis advanced license so I can't use the Split Line at Point tool. Can someone help me with a ...
3
votes
1answer
731 views

Change default layer name in QGIS 2.18

In QGIS 2.18, new vector layers resulting from QGIS tools have a default name related to the corresponding tool. For example, when I perform the "Lines to polygons" operation (under QGIS Vector menu), ...
2
votes
2answers
5k 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, "...
2
votes
1answer
1k views

Getting list of valid layers in TOC using PyQGIS?

To get the list of TOC layer names I used the approach suggested here: for layer in QgsMapLayerRegistry.instance().mapLayers().values(): print layer.name() But this method is not reliable due ...
2
votes
1answer
10k 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:...