I have a polygon shapefile with 1800 records. I want to slim this down by merging together records with either:
a) duplicate/matching area sizes in the Area field
b) matching first 6 letters of a reference ID field.
So below, the 4 'Armes Court' shapes would combine into one and same with the 'Avon Court' shapes etc etc...
There are too many records to go manually merging them togther.
also, why can't i publish this question in a general 'GIS' location? When I click browse places, all the cateogories are really specific. I've had to choose python as perhaps the solution to my question is python...? who knows...
I've made a new text field to copy across the first 6 characters into, do you know what vb/python code I should use in field calculator to only take the FIRST 6 characters over? or copy it all then DELETE the last 4 numbers from the right?
Dissolve wont work as standard on the 2 fields as you require, however do you really need to merge where the areas are the same also, is the first 6 characters of the uniqueID not enough?
(Your rows for "Armes court" will not dissolve into 1 feature as they have different areas)
Anyways, if just the uniqueIDs is just enough, the workflow is:
1) Calculate field using expression:
left( [QL_PROPID], 6)
2) Dissolve using this new field as the dissolve field.
Yes I didn't realise there were two different areas for armes court. I guess what I only want, is to dissolve based on the Unique ID field.
I'll create a new text field to transfer the first 6 characters over. Then I'll dissolve.
I always get confused with the 'left' and 'right' in vb scripts. And whether it deletes or keeps the specified characters.