How to make lyap in a loop run faster?

Hi, I am running a loop to repeatedly solve the Sylvester equation AX+XB+C = 0 with the same A and B but different C in each iteration. The help document of lyap says it transforms A and B into Schur form every time, and in my case A and B never changes.

So I am wondering if there is a way to somehow skip the transformation each time when lyap is called? Or is there some other ways to make it run faster?

Thanks a bunch!

- y

[bym]

make sure you preallocate!