Calculating Sinuosity Using ArcGIS Field Calculator

Question

Trying to calculate sinuosity via Field Calculator (ArcGIS v 10.2.2); VBA

Pre-Logic Script Code:

Dim dblLe as double
Dim dblLf as double
Dim dblS as double
Dim pCurve as Icurve
Dim pFPoint as IPoint
Dim pTPoint as IPoint
Set pCurve = [Shape]
Set pFPoint = pCurve.FromPoint
Set pTPoint = pCurve.ToPoint
dblLe = Sqr((pFPoint.X - pTPoint.X)^2 + (pFPoint.Y - pTPoint.Y)^2)
dblLf  = pCurve.Length
dblS = dblLe/dblLf

Variable =

dblS

I know ESRI has a python script put I am try to run via Field Calculator. Anyone see my error?

Answer 1

If done in Python:

Expression parameter:

getSinuosity(!shape!)

Codeblock parameter:

import math
def getSinuosity(shape):
    length = shape.length
    d = math.sqrt((shape.firstPoint.X - shape.lastPoint.X) ** 2 +
                  (shape.firstPoint.Y - shape.lastPoint.Y) ** 2)
    return d / length

Make sure to use an expression type of PYTHON_9.3.

Also take a look at this tool here. I wrote this a couple of years ago as part of a demo. Under the hood, it's using CalculateField like I've described above.