Questions tagged [features]

Use this tag when asking questions about a representation of a real-world objects on a map.

Filter by
Sorted by
Tagged with
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.
33
votes
2answers
22k views

Reading feature class in file geodatabase using R?

I have a feature contained in a geodatabase that is larger than 2GB as an exported shapefile. I need to run an extract function in R to attribute the polygons with data from a raster file. Exporting ...
27
votes
3answers
67k views

setStyle() function for GeoJSON features - Leaflet

Ok, since I already asked a very long question about this, but since it didn't get any new replies for a while, and not to get confused in details, I will keep this one simple the best way I can. If ...
20
votes
2answers
24k views

How to select features containing specific text string using an expression in QGIS

I need to style a survey parcel polygon shapefile, based on whether the polygon is a mineral claim or not. Unfortunately, the only information on whether a polygon is a mineral claim or not is ...
14
votes
2answers
16k views

How to change the value of an attribute using QgsFeature in PyQGIS?

I would like to update one attribute of a feature. However, I don't know to update it using the feature object. I have to use data provider to update it. layers = QgsMapLayerRegistry.instance()....
13
votes
2answers
12k views

Difference between Copy Features and Feature Class to Feature Class tools?

I have a feature class within a feature dataset in a file geodatabase (FGDB), and I need a copy of it in another FGDB. In ArcGIS 10.1, I've used the "Copy Features" tool, and it looks to be the same (...
12
votes
5answers
3k views

What is the fastest (performance-wise) way to serve PostGIS features?

I'm interested in the fastest way to serve PostGIS features. I can find several WMS improvements and alternatives (MapProxy, TileCache, Mapnik...) but not so many WFS Open Source improvements and ...
12
votes
3answers
23k views

Exporting multiple featureclasses to shapefiles using ArcGIS Desktop?

I have many feature classes in a geodatabase and I need to save/export them into shapefiles. Any Ideas? Click on every single layer -> export is not a good option, due to the number of feature ...
12
votes
3answers
404 views

Distinguishing corridors from fragments in a habitat map

I was wondering if someone has delt with this kind of issue before: I want to delineate fragments based on neighboring pixels of the same class (forest) with a distance threshold of 3 pixels (which ...
11
votes
3answers
23k views

Deleting multiple features easily in QGIS

I have a vector layer being rendered in QGIS. I want to delete various features in the layer. I'm currently deleting each node by selecting the node through node tool and then pressing the delete ...
11
votes
4answers
45k views

Cutting features to do opposite of clipping in ArcGIS Desktop? [duplicate]

What´s the easiest/smartest way of getting the opposite output of the clipping tool? I just need the area of feature A1 which is not covered by feature A2 in a new Layer/File. Now, I get the result ...
11
votes
4answers
16k views

Get all the points of a polyline

I have some polyline feature objects in python. Now I want to get all the points of polylines. For example, if a polyline has start point [0,0] end point [5,5]. Result: [1,1];[2,2];[3,3];[4,4];[5,5]...
11
votes
3answers
2k views

Generating attributes in an automatic way with QGIS?

I want to autogenerate IDs while I create new features. So every time I create a new point, its ID will increase by 1 like the following: Feature 1: id 1 Feature 2: id 2 Feature 3: id 3 How can I ...
11
votes
3answers
8k views

What is a non-geographical feature?

When using the term "feature" in GIS, what is often (if not always) meant is a geographical feature which "is a representation of real world phenomenon associated with a location relative to the Earth"...
11
votes
2answers
8k views

How to use label classes, expressions, and annotations?

I've always found that when it comes to python, vector analysis, QGIS gives ArcGIS a run for its money, hell some of the qgis plugins exceed ArcGIS's performance by a few hours; however, I always have ...
10
votes
2answers
3k views

Feature Count in Legend (QGIS 2.18.2)

Below is a screen shot of my Layers Panel showing two Graduated Category layers. One set of category features (Change in Small Firms (2015-2010)) are accompanied by counts, while the other (Change in ...
10
votes
1answer
868 views

Features in commercial GIS software missing in FOSS GIS?

For example, a program I use (TransCAD) has the ability to do travel time matrices based on minimal data input, which is really useful if you're looking at doing back of the envelope type calculations....
9
votes
3answers
28k views

Displaying properties of GeoJSON in popup on Leaflet?

This is my simple GeoJSON with Leaflet map. I want to display properties as popup but I don't know why it is empty. Can you tell me my mistake? <html> <head> <title>A Leaflet map!...
9
votes
2answers
11k views

How can I unselect a feature in Openlayers?

I am able to identify the selected features on my map using the following line: vector_layer.selectedFeatures I would like to be able to deselect this feature using a standalone function (not an ...
9
votes
2answers
497 views

Quickly browsing of features for the active vector layer?

I often need to view on the canvas the (selected or not) features from the current active vector layer. In this situation, I only need to view something on the canvas, without doing anything on the ...
9
votes
1answer
4k views

How to Verify if a FeatureLayer already exists?

I am currently working on a project where when user loads up their map (mxd) into our system, we create several custom featuerlayers for them. My problem is though, I have no idea how to check if I ...
8
votes
3answers
9k views

Deleting feature class features faster using ArcPy?

I have written this script that recurses through all feature classes in a given set of feature datasets and deletes all their features. It appears to do the job but it runs pretty slowly. Is there ...
8
votes
2answers
2k views

How to sum up values of overlapping polygons in QGIS?

I have large single layers with many features overlapping. Simplified example with 50% transparency: Where the features overlap I want the attributes added together. I manually created the output ...
8
votes
2answers
6k views

what's the difference between spectral signature and features in remote sensing?

I would like to understand if is there any difference or relation between spectral signature concept and features in remote sensing?
8
votes
2answers
7k views

QGIS select feature, “add to current selection” feature

I am trying to perform a feature selection on qgis similar to "add to current selection" interactive selection method in Arcgis Desktop, is that possible? An example: I perform a spatial query and ...
8
votes
1answer
6k views

Geometry from multiple selected features into one geometry

Lets see if I can explain what I'm trying to do. First of all I have developed an AddIn for ArcMap that can take one selected feature (Polygon) on a layer, grab the geometry of that feature, and save ...
8
votes
1answer
4k views

Sharing a Folium Interactive Map w/ Embedded Markers

I have been experimenting with a few Python packages that have great potential for my dissertation research. Since I use pandas for pretty much everything, geopandas was a natural choice for working ...
8
votes
3answers
9k views

How to Count Features in a Feature Type in FME?

I am reading around 120 spatial tables in FME. I would like to export a spreadsheet or CSV using FME that contains the feature name (table name) and the number of records in that table. So far, I've ...
7
votes
2answers
4k views

Applying categorized symbol to each feature using PyQGIS

I want to apply unique symbol to each feature. I have used following code for doing that from qgis.core import * from PyQt4.QtGui import * # supply path to where is your qgis installed QgsApplication....
7
votes
1answer
22k views

OpenLayers: Get Coordinates of drawn features

Can someone help in finding coordinates of drawn features? I am using this example OpenLayers website. I need to be able to export drawn objects as set of coordinates. Posting the code from the ...
7
votes
4answers
1k views

keeping track of edited features QGIS

Does anyone know of a way to keep track of last added or edited features in QGIS? A kind of Editor Tracking tool.
7
votes
3answers
10k views

Openlayers remove previously drawn polygon on starting to draw next one

Objective: At any point of time there SHOULD only be zero/one polygon(s) on a vector layer with a polygon control. I need the previous polygon to be removed as soon as user starts drawing the first ...
7
votes
5answers
6k views

Using OpenLayers Selectfeature get mouse position? [closed]

How do I get mouse coordinates after a SelectFeature, which returns the feature by itself?
7
votes
4answers
5k views

Show/hide features on layer in OpenLayers?

In previous versions of OpenLayers, features on a layer could be hidden by changing visibility to 'hidden' but that does not seem to work on OpenLayers 4. How can features be modified so that we can ...
7
votes
2answers
284 views

Features to stay selected by default in QGIS?

Does anyone know if there's a way to configure QGIS so that when you plot a new feature (i.e. a polygon), it stays selected by default? If I have to select it separately, and it happens to fall on ...
7
votes
1answer
1k views

Moving a vector layer 20m to the west on QGIS

I have a vector layer of power lines for an area, the shapefile that I was given is actually around 20m to the west of where I know the power lines are actually supposed to be, as they are supposed to ...
7
votes
1answer
1k views

Feature/label visibility based on spatial relationship to index feature using data-driven pages

I'm creating a series of maps using ArcGIS data driven pages. I know how to display features that share an attribute with the index layer, but is it possible to display features (and similarly, labels)...
7
votes
1answer
182 views

Combine multiple adjoining parts of a single feature

In QGIS, one polygon feature resulted from merger of several adjacent polygons. This one new polygon feature has a single line through it that I would like to eliminate. When hovering over individual ...
6
votes
4answers
2k views

Can someone help me identify this part of the map?

I'm sure 1 is a road, but what are those bumps on the side? I'm guessing 2 is a footpath. I have no idea what 3 is, if you don't know what it is, fine, let's leave it at that. I searched for what ...
6
votes
3answers
2k views

Mapping a feature from the attribute table in QGIS?

I currently finished adding all the needed attributes for my research. I would like to map these attributes. Is there any way to do so? The original method I was taught was to select: on the map and ...
6
votes
2answers
657 views

Is there a maximum number of features that QGIS can save into a shapefile?

I have a very large .gdb that I want to reduce to my study area. Unfortunately, the study area is still quite big. I could select features that intersected my study area but when I tried Export > ...
6
votes
2answers
7k views

Copying selected (targeted) features to new shapefile using ArcPy?

I am trying to copy specific attribute table rows from one shapefile to a new shapefile that will contain only the specified rows in its attribute table, that is, if a field GDP_TOP10 = 1. I am ...
6
votes
3answers
2k views

How to find out what features /tags are included in an .osm or .pbf file?

I would like to load osm data into a postgis (postgresql) database. In How to load OSM data into PostGIS preserving all Tags? there has been a solution posted: Download the OSM files (in .osm format)...
6
votes
2answers
7k views

Merging overlapping line segments in ArcGIS Desktop?

I'm working with fish distribution data, and have combined several 24k habitat maps into a single layer that I'll call "critical habitat" In merging multiple distributions into one dataset, there are ...
6
votes
2answers
992 views

What does feature mean in QGIS?

I can't understand the meaning of feature in QGIS QgsFeature class. How it is related to layer and geometry? I have read QGIS documentation but I can't understand what is feature.
6
votes
1answer
2k views

Deleting all but one feature from a set of features with the same ID, keeping one with largest area?

I have a large polygon layer in which most of the polygons have a unique name in a text field. Of the hundreds that are not unique, there will be 2-4 polygons with the same name but different ...
6
votes
3answers
13k views

Deleting multiple feature classes simultaneously?

I created a number of feature datasets to temporarily store the output of some ModelBuilder models. Each dataset contains several thousand feature classes, and the idea was that I could just delete ...
6
votes
3answers
19k 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 OpenLayers.Geometry.Point(pt....
6
votes
3answers
2k views

Fastest way to merge a feature

I am writing a arc engine application that can take a shapefile, and merge a set of polygons together. Here is the code that I am using to merge the polygons: private static void mergeFeatures(...
6
votes
2answers
235 views

What event is fired when a feature is edited?

When the user draws a new feature (line, point, etc.) in ArcMap, there are null attributes. If the user enters values in these null fields what is the event that is fired? I want to control the ...

1
2 3 4 5
13