Getting "Improper Boolean" Error

[TravisClemons]

Im trying to have the "Vertical Strut Control" toggle the Yes/No based of its length. 

[David_W_Koch · Accepted solution]

@TravisClemons 

Revit formulas do not work the way you have it written.  Formulas control the value of the parameter to which they are assigned.

I have not tested this, but believe something like this should do what you want, assuming that when Vertical Strut Type Control is less than 9'-0" you want Vertical P1000 to be checked and Vertical P1001 to be unchecked and the opposite if the value is 9'-0" or greater.

Formula for Vertical P1000:  Vertical Strut Type Control < 9' 0"

Formula for Vertical P1001:  not(Vertical Strut Type Control < 9' 0")

An alternate formula for Vertical P1001 could be:  not(Vertical P1000)

Delete the formula for the Vertical Strut Type Control parameter.

If you want some other result, describe what it is.

[ToanDN]

Edit: Answered. Nevermind

Enter formula for the two y/n parameters:

Vertical p1000: Vertical Strut Type Control < 9'

Vertical p1001: not (Vertical p1000)

[barthbradley]

For what it's worth to you, here's the formulas to push yes/no value directly: