Latest Contributions by RichardFairhurst

I agree that the user can use the Project tool to convert from a Geographic Coordinate System to a Projected Coordinate System before using my tool.  However, I am not familiar with the best projection choice for Germany, so I was not prepared to do that with this particular data.  Anyway, using a Projected Coordinate System would be a requirement of the line network buffer tool I am building at this stage and that requirement will be specified in the help and error messages for the tool by the time I release it. Thanks for the feedback on the buffers.  I spent about 6 hours tweaking the results.  Essentially anywhere the cut between two communities bends, I drew that.   Bending cuts are not precisely measured to split between communities exactly 50/50 and is only eye ball accurate in those cases.  But since these cuts are within waters (rivers and coastal areas) obviously controlled by Germany and not another country, I was not too concerned about getting better precision. For straight line cuts, the methods involved used a mixture of tools, some of which would require an Advanced license.  I had to use the Polygon to Line tool to extract the full community buffer outline and each communities outline as a line.  I had to delete all community boundaries that touched another community (easy to do if topology is perfect).  The Feature Vertices to Points tool was used to extract points from the ends of each community line for LR processing.  I also used the Features to Polygon tool to combine a set of lines at a normal angle to the buffer outline with the buffer to cut it into separate polygons.   The Feature Vertices to Points tool was used to extract points from the mid point of each community line and the Spatial Join tool (Basic license) was used to transfer attributes from the mid points to the cut up polygon output of the Features to Polygon tool. The cut lines that were at a normal angle to the buffer outline were created with LR tools and techniques, which work with a Basic license.  With these tools I had to categorize the country outlines into groups that would build continuous non-branching, non-looping portions of the country outline into routes and then used the Create Route tool to build simple routes.  I used the Locate Features Along Route tool to create an event table of the community outside end points on the routes.  I used the Make Route Event layer to create offset points at 2 km from the Germany outline.  I used the Points to Line tool to create a line segment between the point on the line and the LR offset point. The straight cut lines were all examined and where the normal angle to the line was not the best fit to the buffer I moved the offset end to a location that I liked manually.  I would estimate I did this for about 15-20% of the cut lines.  Moving the ends took longer than using the tools to get the 80% of correct cut lines, but was necessary. Anyway, I hope your client is happy with the result. ... View more

Silvan: This is where an adaptation of my Turbo Charging Data Manipulation With Python Cursors and Dictionaries can help overcome the limitation of the DA cursor to control record order (which is a slow database operation even if it worked) and instead take advantage of the speed of a dictionary.  The dictionary keys can be sorted and will also let you quickly access them randomly as you write the data back to the cursor. To do this run a search cursor first through the entire record set and create a dictionary of sortable keys with initial values of 0.  Process the sorted dictionary keys and increase their values using a counter.  Finally run the update cursor and write to it using the dictionary.  I would use both your Nummer field and the ObjectID field values to be sure all keys are unique, since otherwise a repeated value in Nummer would mess up the counter.  (You are not limited to using the Nummer/ObjectID combination and this is how you can also set up relationships based on multi-field unique key values to overcome the limitations of single field joins).  The speed of this code will be virtually as fast as just running the update cursor. So here is the code (replace 'COUNTER' with your actual counter name field): import arcpy lyr = YourLayer # replace this with your layer name fields = ['Nummer', 'OID@'] # set up a dictionary and counter dict = {} counter = 0 # Use list comprehension to build a dictionary of Nummer/ObjectID tuple keys dict = {(row[0:]):0 for row in arcpy.da.SearchCursor(lyr, fields)} # Sort the dictionary keys and increase the counter values based on the key order for value in sorted(dict.keys()):     counter += 1     dict[value] = counter # Write back to the layer with an update cursor using the dictionary. Change 'COUNTER' to your counter field fields = ['Nummer', 'OID@', 'COUNTER'] with arcpy.da.UpdateCursor(lyr, fields) as cursor:     for row in cursor:         row[2] = dict[(row[0],row[1])]         cursor.updateRow(row) ... View more