A representation of a real-world objects on 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?
11
votes
5answers
1k 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 ...
11
votes
2answers
4k 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 ...
11
votes
1answer
1k views

Dealing with overlapping features in OpenLayers

If users create a polygon feature that completely overlaps another one, like this … … then there's no way you can select the inner feature, i.e. the one that's overlapped by the other. I'm ...
10
votes
3answers
399 views

What are some of the features available in non-FOSS GIS software that you'd like to see in your favorite 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 ...
10
votes
3answers
313 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 ...
9
votes
3answers
3k views

What is quickest way to select polygon by point in ArcGIS 10 using ArcPy?

I keep thinking that I must be missing something, but there does not seem to be a tool in ArcGIS 10 to select features (in particular polygons) from a layer at a point (X,Y) location via ArcPy. The ...
7
votes
3answers
2k views

How to delete feature class features faster (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 ...
7
votes
4answers
4k 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: ...
7
votes
3answers
3k views

How to export multiple featureclasses to shapefiles?

I have plenty features in a geodatabase. I need to save/export them into shapefiles, because my mate works with Manifold, which is not able to read geodatabases. Any Ideas? Click on every single layer ...
7
votes
2answers
222 views

How to remove long linear strips from polygons?

I have a polygon layer representing impervious land cover. This was taken from a land cover raster dataset. The impervious data represents all impervious surface that is not buildings or roads. I ...
6
votes
2answers
121 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 ...
6
votes
1answer
2k views

How to select multiple Features from multiple Layers in OpenLayers?

Is there a way to select multiple features from multiple vector layers by using clickTolerance in click? I checked the documents of getFeature control and selectFeature control, seems not work in ...
6
votes
1answer
2k 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 ...
6
votes
2answers
237 views

Why am I getting duplicate ghost points (features), i.e., one point in the feature class but two points?

When editing some of the attributes in a point feature class in ArcMap 9.3, duplicate labels started showing up. When I click on the point, I discovered that the point has duplicated itself BUT there ...
6
votes
1answer
112 views

How to store and serve data and its progress over time in GeoServer?

I recently started working with GeoServer and stored some shape files. I successfully can retrieve the data as JSON. The data I want to maintain in the database changes over time. I do not want to ...
6
votes
1answer
377 views

Display Feedback “Stutters” When Moving Features

I have a custom tool for moving features that implements IDisplayFeedback and geometry-specific CoClasses to show the user where they are moving the feature. IMovePolygonFeedback polygonFeedback; ...
5
votes
2answers
943 views

What's the difference between “Copy Features” and “Feature Class to Feature class”

I have a feature class within a feature dataset in a 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 (according to the ...
5
votes
1answer
751 views

Drag a Feature in ESRI, ArcObjects Engine (AxMapControl)

I'm trying to implement moving a point feature in a custom C# ArcGIS Engine application on an AxMapControl. I've already created a custom tool to do some other things. And I can track when the user is ...
5
votes
5answers
447 views

Where to find a list of geographic 'objects'?

Is there an extensive list of geographic "objects", "entities" or "features" that can be discovered in the geographic environment, relatively static and therefore can be geo-located and represented on ...
5
votes
3answers
341 views

Selecting polygons by number of sides

I'm using ArcGIS 10 to build some figures for a journal article. One is a figure of an unstructured finite element mesh of triangles spanning the western Atlantic Ocean. I exported this mesh from ...
5
votes
2answers
609 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 ...
5
votes
3answers
5k 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
3answers
2k views

Slow IE8 responsiveness with OpenLayers and many features

Background Adding about 700 sites to an OpenLayers Map. Firefox 11 and Google Chrome display the sites just fine. IE8, which is the organization's standard and will not be upgraded for the ...
5
votes
2answers
2k views

Clip (Analysis) in ArcGIS 10 running indefinitely

I am attempting to clip a series of polylines (cross sections) using a single polygon. There are approximately 2400 polyline features in my input featureclass. Is this too large for the Clip tool to ...
5
votes
1answer
2k 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 ...
5
votes
2answers
550 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 ...
5
votes
3answers
862 views

How to update feature positions with clustering in OpenLayers?

I have an OpenLayers 2.12 map with a vector layer with a cluster strategy. All the static behavior is how I want it. Now I'd like to add the possibility to update the features' position. I do this ...
5
votes
1answer
174 views

How can I increase performance on inserting features with polygon geometry?

I have a problem when inserting features with polygon feature class in FGDB. This is my code: ... initialising some fields (does not affect performance) m_featureBuffer.Shape = ...
5
votes
1answer
1k views

OpenLayers Selectfeature get mouse position

I'm have been searching for several hours and do not find a way to get mouse coordinates after a SelectFeature, which returns the feature by itself. I saw that this has been asked several times ...
4
votes
2answers
656 views

How to copy selected (targeted) features to new shapefile using ArcPy?

I'm 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'm using ...
4
votes
1answer
420 views

Is there a way to get the X,Y from a feature class?

I currently have an instance of a selected feature class, and I want to be able to get the midpoint X,Y (if its polygon) or the X,Y (if its IPoint) of the feature from the layer, is there some build ...
4
votes
3answers
3k 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 ...
4
votes
2answers
203 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 ...
4
votes
1answer
408 views

Need to delete all but one feature from a set of features with the same ID, keeping the one with the 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 aren't unique, there will be 2-4 polygons with the same name but different ...
4
votes
2answers
44 views

Need to merge overlapping line segments

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 ...
4
votes
2answers
394 views

How to select features that intersect but don't touch (using ArcObjects)?

So how do I do that? ArcMap's Select By Location selects also all features that touch, but I only need the ones that actually intersect the area. I currently use ...
4
votes
3answers
2k views

How to delete 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 ...
4
votes
1answer
120 views

How to convert a column of numeric IDs to letters?

I'm working with qgis 1.8.0. I divided a map into 500 features (small rectangles), and now I have the doubt if there is any way to change the ID of the attributes from numbers to letters? When I did ...
4
votes
1answer
5k views

Assign Icons to specific points dynamically in OpenLayers

I have a json file describing features on a map (routes, points etc) points include places of interest such as airport, harbor etc. Is there a way to assign icons to these points? example: have a ...
4
votes
1answer
6k views

How to get features in Openlayers vector layer

What is the exact API to get all features in a vector layer in OpenLayers? Suppose I have the "map" object, within which is a "Vector Layer": how can I obtain features in the layer?
4
votes
3answers
8k views

Hover/Popup feature problem

im really having an issue here. I am trying to realise a map where i can hover over the features and they get highlighted (works), then i want to be able to click them (works) , i also want a div to ...
4
votes
1answer
738 views

merge selected features and programming

I have a shape file with UK districts and unitary authorities. In the past, using commuting patterns, I worked out a new geography which is close to travel to work areas. I now would like to create a ...
4
votes
1answer
229 views

Retrieve data from FeatureClass

I have : FeatureClass (Structure) column (Type) column (OID) I am trying to get the (Type) for specific OID. I tried to use this code but it dose not work. IFeatureWorkspace featureWorkspace = ...
4
votes
3answers
458 views

Can I prevent features from being created outside an OpenLayers map?

In our app, we allow users to create features on maps. The boundaries of these features will later be converted into real-life latitude/longitude coordinates, but does not make sense if features are ...
4
votes
1answer
84 views

Is it possible show the feature attributes dialog when I add a feature in code?

I want to know if it is possible to make the feature attributes dialog in Qgis show up when I add a feature by code using: QgsVectorLayer::addFeature( tFeature ) This is available when I add ...
4
votes
1answer
104 views

Creating a feature of a part of a state boundary from a shapefile of U.S. States

I have a shapefile of U.S. states. I want to create a feature layer from it so that I can do a Near analysis with it. Suppose that I am interested in the Georgia boundary, but only the part of ...
4
votes
1answer
1k views

slow to draw mapservices after access featureLayers within an ESRI Mapservice using Javaascript API

I am working on creating an online map using ESRI mapservices as a basemap and existing mapservices on our arcserver.. The problem I am running into is that the mapservices we have here are really ...
4
votes
1answer
1k views

How to integrate OpenLayers and ArcGIS Server?

I am using the OpenLayers JavaScript API within a web application. I am displaying non-base layers hosted on an ArcGIS server. When I load the ArcGIS layers, I load them using ...
4
votes
0answers
149 views

What open source solution would work best for auto extracting features from satellite images? [duplicate]

Possible Duplicate: Feature Extraction - Land cover I have been looking for an open source solution which would allow me to define a region (or collection of images) and extract features ...