50
votes
6answers
20k views

What are Esri's new “ArcGIS for Professionals” and “ArcGIS Pro”?

After looking through all the stuff that was released or talked about at the Esri UC 2013 I am still genuinely confused by what ArcGIS for Professionals is. I will admit that it looks pretty cool, ...
49
votes
4answers
18k views

LatLon or LonLat, what's the “right” way to display coordinates and inputs?

I'm trying to get a sense if this is an issue for others or every input/output should be labeled so user is not confused and just go with it? I think almost everyone pronounces it as "LatLon". Who ...
24
votes
8answers
8k views

When Versioning with ArcSDE can posted edits be cancelled or rejected?

I am using ArcGIS 9.3.1 and attempting to work with an SDE geodatabase (with one polygon feature class) that has already been registered as versioned. I'm new to versioning and am still trying to ...
27
votes
4answers
7k views

How can I switch line direction in QGIS?

Something that is hopefully pretty easy. I would like to be able to swap the direction of a polyline/line in QGIS. I made a custom tool to do this in MapInfo a couple of years ago, however I can't ...
27
votes
2answers
17k views

How can I convert data in the form of lat, lon, value into a raster file using R?

I have a data set of values over a km grid in the continental U.S. The columns are "latitude", "longitude", and "observation", e.g.: "lat" "lon" "yield" 25.567 -120.347 3.6 25.832 -120....
24
votes
5answers
21k views

Is ArcSDE no longer needed at ArcGIS 10.1?

Through my frustration of not finding the post-installation wizard with ArcSDE 10.1 and being unsuccessful with the command line tool to start an SDE service on our SDE databases, I found I was able ...
57
votes
3answers
51k views

What is the difference between WGS84 and EPSG4326?

What is the difference between WGS 84 and EPSG 4326? It seems like for a given dataset it might be both WGS 84 and EPSG 4326.
22
votes
1answer
5k views

Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected DEM Data

This is somewhat of a theoretical question stemming from some discussions with colleagues on the topic of implications with delineating basins with projected (e.g., Albers Equal Area) vs. unprojected (...
16
votes
3answers
2k views

Algorithm to find out points of inflection for a polyline

I am trying to find out the points of inflection , i.e. points where the curves in a line start and end. If you look at the image, the green line may be a road or a stream, and the black points are ...
11
votes
4answers
4k views

Connecting line features and determining the length of the longest line

I have a line feature (see image) representing a river that I created using the Stream_to_Feature tool. The attribute table contains several records representing different lines - the problem is the ...
24
votes
10answers
33k views

Adding Attribute data to shapefile?

I can display a shapefile in openlayers but I need to add some attribute data. I can open the dbf file in excel but there is no save as option in excel to the updated file as a dbf. What is the ...
22
votes
5answers
5k views

How to create regular point grid inside a polygon in Postgis?

How to create, inside a polygon, a regular grid of point spaced x,y in postgis? Like the example:
21
votes
3answers
2k views

Packing Polygons within polygon

I have a Boolean raster. In the grey areas of the raster I would like to fit a given size polygon within a contiguous extent. Basically, I have an irregular polygon, and i would like to "fit" a ...
11
votes
5answers
3k views

Simplifying polygons to linestring

I would like to simplify some polygons that represent rivers into linestrings. I assume that holes in polygons can be omitted. Anybody has some good idea how to simply do it? It would be nice, if it ...
27
votes
5answers
4k views

Generalizing polygon file while maintaining topology in QGIS?

I have a polygon Shapefile, which I need to generalize. How can I generalize the poligons and ensure that there are no topological errors like "slivers". I already tried: Vector -> Geometry Tools ...
17
votes
7answers
6k views

Creating trade flow maps in ArcGIS for Desktop (or any free software)?

I am trying to represent trade flows on a world map where the size and direction of arrows indicate the exports/imports of a given country. This type of map is commonly found in magazines and ...
16
votes
8answers
35k views

Extracting coordinates of polygon vertices in ArcMap?

I've got about a dozen polygons in a feature class loaded in ArcMap 10, all in geographic WGS 1984. How do I easily obtain the coordinates associated with each vertex of each polygon in that feature ...
10
votes
1answer
745 views

How to automatically populate fields instantly?

I am looking to create an attribute table where the first field is a drop-down menu (I have achieved this by using the 'value map' edit widget), but I'm struggling to find a method for the next part; ...
7
votes
1answer
26k views

How to change the unit of measure from degrees to meters in QGIS?

I am running QGIS 1.7.0 on windows, and I donwloaded a shapefile of census block group boundaries from TIGER. This file appears to be in the WGS 84 coordinate system, and when I open it in QGIS the ...
9
votes
2answers
820 views

Creating summary table of symbology of all datasets in multiple MXDs?

This is related to the following Retain ESRI symbology in Mapinfo TAB . As an initial step (in arcpy) I want to access the symbology of all the datasets and create a document which has the details of ...
9
votes
6answers
9k views

How to fix quickly a lot of geometry validity errors in QGIS?

I am working on ownership data at a US county level. I have one shapefile per county that contains thousands of tax parcels. I need to dissolve the polygons representing parcels owned by the same ...
8
votes
2answers
9k views

Rotating a vector layer in QGIS with qgsAffine (or other method)?

I would like to rotate a set of vector points in QGIS an arbitrary number of degrees around a central point (or arbitrary point). This is similar to a recent question about creating a regular grid; ...
8
votes
3answers
12k views

Remove lock on feature class

When i try to delete a feature class , after or during the use of an Arcgis engine app which uses the same feature class i got an error concerning the lock , so i can't get ride of this lock until i ...
8
votes
4answers
7k views

How to split a vector in equal smaller parts in QGIS or similar?

i want to divide a shapefile with many tiles into a lot of smaller tiles. I am searching for a smart solution, because manual edits are out of questions Anyone can help or know a nice function?
5
votes
2answers
1k views

Guidelines for using ArcObjects from Python

By far, How do I access ArcObjects from Python? is my most read and referenced Q&A on GIS Stack Exchange. In spite of that success, it's probably one of my weakest areas when it comes to actual ...
12
votes
2answers
29k views

How to crop Shapefiles in QGIS?

I need to clip a large and very detailed .shp file in QGIS showing environmental data similar to a temperature map. Is there something like the very simple crop tool alike in photoshop where you can ...
12
votes
2answers
8k views

How to check Topology in QGIS?

I have two Shapefiles with Polygons ( City and Forerst) Is there a Plugin who is able check the topology (QGIS)? Like "Knots do not overlap" or something like that? I dont want that they overlap. ...
11
votes
2answers
331 views

Can labels for overlapping points be combined/merged into one label?

I have points representing sample locations. Often, multiple samples will be taken in the same location: multiple points with the same location but different sample IDs and other attributes. I'd like ...
8
votes
2answers
1k views

How to create an oriented buffer using arcpy?

I would like to create an oriented buffer for every polygon in my shapefile using arcpy. By oriented I mean that I have two angles a1 and a2 that constraint the direction of the buffer. This is ...
16
votes
2answers
11k views

Getting list of selected features in ArcGIS for Desktop using Python code?

I have a question regarding selections in ArcGIS for Desktop. Assumed I have one layer in ArcMap and I have selected two of five features. Is it possible to get a list of all selected features by ...
16
votes
3answers
3k views

How do I find the distance between two coordinates in an ellipsoid?

Lets say I have two sets of latitude and longitude. How do I find the distance between the two locations if I assume the earth is a perfect ellipsoid (with an eccentricity of 0.0167)?
14
votes
1answer
2k views

Is there a way to access QGIS plugins in Python?

Is there a way to access QGIS plugins in Python? I'd like to write a script to do some geoprocessing, and I'd like to use the clip, regular points and convex hull tools in fTools, as well as the Road ...
10
votes
4answers
4k views

Finding centrelines from polygons in QGIS?

I was wondering if there is a way to create centre lines from polygons in QGIS? I have a polygon layer, but ideally need the centrelines as a separate file.
9
votes
2answers
3k views

How to build an artificial 'dam' across a river?

I have a DEM. Created all files related to watershed including accumulation, direction, streams etc... I'm stuck creating a dam. I request you to please let me know how to build an artificial 'dam' ...
6
votes
1answer
7k views

Shortest distance from point to line (big dataset)

What is the best method to calculate the distance from the nearest road for a series of address points in QGIS, having a very big dataset? (QGIS 2.0.1, Win XP) I read the answers to previous similar ...
6
votes
3answers
5k views

How to read Greek fonts (ISO-8859-7) in shapefile attributes within QGIS 1.8.0?

I'd like to ask whether there is a way to read greek fonts in a shapefile's attribute table within QGIS 1.8.0.
15
votes
4answers
2k views

algorithm to place maximum number of points within constrained area at a minimum spacing

I have a polygon layer that describes a constraint; I wish to add points within this area. I want to add as many points as possible, but they must have a minimum spacing between them. Is it possible ...
8
votes
2answers
22k views

Create polygon layer from polyline layer

Our systems expect polygon shapefiles, representing a collection of non-intersecting and geometrically valid (multi)polygons. Specifically, farm fields. We often receive our representations of farms ...
8
votes
3answers
2k views

How to interpret GRASS v.kernel results?

GRASS manual reads: v.kernel - Generates a raster density map from vector points data using a moving 2D isotropic Gaussian kernel ... Ok, but how do I interpret the results? I understand that v....
7
votes
3answers
7k views

Finding nearest raster cell value based on vector point?

I have two layers in ArcGIS: One is a vector point and the other is a raster layer. I want to append the value of the raster data grid to the vector point. The problem is the vector point is away from ...
5
votes
1answer
798 views

Calculate population within radius

I have population data matched with polygons and a set of points that I have drawn buffers around. Assuming that the population within each geographical area, i.e. the polygons, is evenly distributed, ...
4
votes
2answers
15k views

How to Extract by Attribute Using ModelBuilder with User Input?

Using ModelBuilder, I want to create a tool that will let a user choose the value or values that will be used to extract a shapefile. I have a parcel layer with a "Parcel_Type" field. I want the user ...
3
votes
1answer
4k views

How do I find vector line bearing in QGIS or GRASS?

How can one extract the bearings from a set of lines in a vector file? I'm trying to find the bearings of several straight vector line segments (simplified contour lines, actually) and can't figure ...
19
votes
2answers
5k views

Adding new group layer with ArcPy?

Does anyone now how to add a group layer with Python in ArcGIS Desktop 10? I can use arcpy.mapping.AddLayer but surely this is only for an actual layer as opposed to a group layer. so far I have ...
12
votes
5answers
1k views

Calculating visible sky percentage?

Can anyone explain, as simply as possible, how to calculate the visible sky percentage? I have done a satellite survey and have worked out the height of buildings and the distance between them. ...
10
votes
2answers
2k views

Inserting newlines in Rectangle Text elements via ArcPy causes overlap?

I ran across an issue the other day when I tried to use ArcPython's mapping module to edit rectangle text elements with newlines (\n) in an ArcMap document. Here's what the output looked like: ...
9
votes
1answer
6k 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?
8
votes
3answers
6k views

How to re-order fields permanently using ArcGIS Make Query Table tool?

In the Answer to somebody else's question it was stated that the Make Query Table tool could be used to re-order fields in tables and feature classes permanently. However, when I open the dialog for ...
8
votes
6answers
2k views

Divide polygons into *n* number of groups of equal counts with ArcGIS 10.2

One of my tasks for work is to divide parcels into groups. These groups will be used by agents to talk to property owners. The goal is to make the agent's job easy by grouping parcels that are near ...
8
votes
1answer
4k views

How to force ArcGIS to recognize a text field in a CSV file?

Related to Data-type detection in ArcGIS table loading I have a CSV file which contains a mixture of numeric and text fields: ID,Txt,Int,Dbl 12345,abc,45,56.78 12346,9,65,23.12 12347,10,66,23.13 ...

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