how to control % as a variable?

[trungta]

Hi everyone, I'm new to Cityengine, I'm trying to create my first ruler file and I'm wondering how to control a % value? Please see attached picture. Thank you for everyone.

[romainjanil · Accepted solution]

//use the p() function probability for true in [0,1], instead of percentages

attr my_prob=0.5

base-->

case p(my_prob): X //true

else :Y  //false

[trungta]

Thank you very much, your solution has solved my problem