Plot history for principal stress- maximum and minimum

How to plot history for principal stress- maximum and minimum in udec.
I tried Block zone history stress-p max 0,0

Binu
There is no command like you mentioned in UDEC ver 7. You will have to write a small fish function to get principal stresses. However, the command “pr zone stresses” lists the principal stresses in the zones.
Jay

Thank you Jay.

Can you explain more on fish function to get Principal stresses.