Vector variable PEGU having length of 19710, which is the length of y1, seems to be popular on this forum Out of memory. Type HELP MEMORY for your options - #4 by zhang . It would be better to keep follow on questions on the same topic in the same thread.
As for avoiding the for loop, so as to speed things up, as I wrote at Rotated_lorentz - #5 by zhang
I don’t know of a way to do that without a loop. If someone else does, please post it.
However in YALMIP, the cone command can be used in a vectorized (matrix) fashion to accomplish this. That should makes things much faster.