Scalar relationships ArcGIS

Question

I have point data which has a number of fields/columns, each of which is at a different scale. I'm looking to find a way of constructing a very simple index which would combine this data. Say I have 3 levels of scale (so 3 fields) - small, medium, large. Each of the points either has or hasn't got a text string at each of those levels. I'm looking to assign a number (or not) depending on whether the text string is present or not, and aggregate that data.

Basically I want to see if there are patterns in the presence/absence of text strings at these different scales (possibly re-combining the value given to each of them in more than one way). I'll then figure out a way of showing this map format (Arc). I don't think I've been very clear but please ask if you need clarification.

Here's a sample table with something along the lines of what I was thinking of doing (in grey). I'm not sure this will give me the outcome I need - ideally each column should have a different weighting reflecting relative size. But should give a rough idea of the sort of thing I was thinking of doing.

Answer 1

I think the easiest way would be to use Field Calculator. Assuming you want a 1 if text is present and a 0 if there is no text, the following will do the trick:

There are no truly blank values in a shapefile (it's stored as a single space), so the code is slightly different for shapefiles vs. Geodatabases.

Parser

Python

Code block

#For GDB
def scalar(textfield):
    return 0 if not textfield else 1

#For shapefile
def scalar(textfield):
    return 0 if textfield == " " else 1

Expression

scalar(COUNTRY)

Repeat for the other two fields.

Answer 2

I still don't fully understand the problem, but given this:

Each of the points either has or hasn't got a text string at each of those levels. I'm looking to assign a number (or not) depending on whether the text string is present or not, and aggregate that data

You could approach this with some kind of conditional statement within a loop. In pseudocode:

for each point in pointLayer
  if street is not null then calculate value = Street
  else if city is not null then calculate value = City
  else if country is not null then calculate value = Country
  else calculate value = error

You could do this in Python using an UpdateCursor