@User (@User ) xschem can display result of equations, however if L and W are set as parameters, with parameters defined somewhere else (perhaps spice .param definitions) this won't work. See below symbol with a sample R=.. where res value is an equation, and the correspondent symbol definition. I have set a random resistivity value (1200), you must pick the correct value from models.

Thanks Stefan. I didn't know how to do this in TCL, so the example is helpful. I can use sheetrow R, although I believe there are edge effect and contact R in the full model. In the device documentation, it looks like skywater does have generic R models and symbols for both poly high and xhigh, which do allow W to be varied. They show a symbol with a computed R. That screen capture presumably is from their example in Cadence.

@stefanoaz the tcleval(...) argument is forwarded by xschem to the tcl parser for evaluation, after substituting the "@var" xschem variables. Normally xschem does only variable substitution and does not do a tcl evaluation on parameters that are not enclosed in a tcleval(...) construct, this is for performance reasons. I think Cadence does something similar, perhaps in a more comprehensive way (may be resolving recursive param definitions). If you know the equation (may be more accurate and more complex than the simple

rho*L/W

) you can add the computed R to the generic resistors too.