topic Re: Field calculator in ArcMap Questions

Field calculator

FOUADHAMDAN_SAAD — Fri, 11 Mar 2022 07:48:13 GMT

Hi community....

I need your help to create python script to calculate the value of the field that called "code" type short integer according to following condition:

def reclass(industrial_area):

if (industrial_area > two_third_neigh_area):

return 13

elif (industrial_area > one_third_neigh_area and industrial_area< two_third_neigh_area):

return 16

elif (industrial_area < one_third_neigh_area):

return unclassified

I tried to apply the above if statement but I got this message:

Re: Field calculator

DanPatterson — Fri, 11 Mar 2022 10:02:06 GMT

The def needs to have the other field names passed to it since it has no values for them. You only pass the function 1 field name (industrial_area). And I would check ArcMap's syntax for passing field names to functions eg do they need to be enclosed in square brackets, exclamation marks like in ArcGIS Pro)

Re: Field calculator

KimberlyGarbade — Fri, 11 Mar 2022 10:23:29 GMT

You didn't include the other fields you were comparing in the function definition.

Re: Field calculator

JayantaPoddar — Fri, 11 Mar 2022 10:48:39 GMT

In the reclass() function you have defined a single variable "industrial_area", whereas you have called three variables in the code "industrial_area", "one_third_neigh_area", "two_third_neigh_area".

You should add three variables in the function, and also define the appropriate fields in the expression.

Moreover, I don't understand "unclassified"? If this is a value, it won't fit in a Short integer type. You could replace it with values like 0 or 99.

e.g.: Assuming the layer has three numeric fields viz., "industrial_area", "one_third_neigh_area", "two_third_neigh_area"

Expression:

reclass(!industrial_area!, !one_third_neigh_area!, !two_third_neigh_area!)

Code Block:

def reclass(industrial_area, one_third_neigh_area, two_third_neigh_area): if (industrial_area > two_third_neigh_area): return 13 elif ((industrial_area > one_third_neigh_area) and (industrial_area< two_third_neigh_area)): return 16 elif (industrial_area < one_third_neigh_area): return 99

Re: Field calculator

FOUADHAMDAN_SAAD — Fri, 11 Mar 2022 13:01:01 GMT

Thank you Sir.

I applied that and it is work perfectly.

I appreciate all replays.