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I downloaded the georeferenced event dataset (top left) from this website: http://ucdp.uu.se/downloads/ It consists of coordinates of violent conflicts which differ in time and space. My aim is to connect the coordinates of one country during the same time (say a month) in a way that it forms a convex area. In other words, I want to create a polygon by connection only the outer coordinates with each other. I want to do this for every country for each time period; therefore, only an automatised process will do.

If you would like to see a picture, you can have a look at the code book of the top right(!) dataset. In case you wonder why I don't simply download the top right dataset: The data is only available until 2010, but I need it until 2014.

I work with the trial version of ArcGIS Pro 1.3

I have worked with ArcGIS before, but this is a few years ago and I used it for quite basic procedures.

  • I'd be using R or Python for this, no need to put a UI in the way. It's a pretty straightforward workflow for geospatial programming – mdsumner Aug 16 '16 at 9:13
  • Thanks, I can try with Stata or ask if someone here knows how to do it with R or Python. – Christian Aug 17 '16 at 10:22
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Input:

enter image description here

Workflow:

arcpy.Dissolve_management("crime_points","C:/FELIX_DATA/SCRARCH/SCRATCH.gdb/crime_points_Dissolve","CID","#","MULTI_PART","DISSOLVE_LINES")
arcpy.Buffer_analysis("crime_points_Dissolve","C:/FELIX_DATA/SCRARCH/SCRATCH.gdb/Buffers","0.5 Meters","FULL","ROUND","NONE","#")
arcpy.CalculateField_management("Buffers","Shape","!Shape!.convexHull()","PYTHON_9.3","#")

Output:

enter image description here

  • Thanks a LOT for the code! This looks exactly like what I need to do. I will try this out as soon as I have time. Take care! – Christian Aug 17 '16 at 10:23
  • Ok, I tried it out. I replicated the commands underlying the first two lines of code without problems, but when I use Calculate Field, I receive this error message:"ERROR 999999: Error executing function. Unable to update area or length field in response to shape update Failed to execute (CalculateField)." Any idea what went wrong there? – Christian Aug 18 '16 at 15:06
  • Try with Shape file and editing mode – FelixIP Aug 18 '16 at 18:24
  • Also use union of inputs in environment settings extent – FelixIP Aug 18 '16 at 18:26
  • It seems you are jumping over time meridian. All shapes but points having issues with it. Try with country sitting in single hemisphere. – FelixIP Aug 18 '16 at 19:03
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The answer by @FelixIP should work using any license level but if you have an Advanced level license then ArcGIS Pro can create your convex hulls using the CONVEX_HULL option of its Minimum Bounding Geometry tool which:

Creates a feature class containing polygons which represent a specified minimum bounding geometry enclosing each input feature or each group of input features.

You would use its group_option of LIST and the field(s) you want to group the points by.

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