[firedrake] Accessing values of a block matrix system

Dear Firedrakers, I'm trying to compare the matrices I get from matlab to the ones generated in Firedrake, but I've run into some issues: A = assemble(a, nest=True) print A.getValues(1,1) gives me File "compressible_stratified.py", line 137, in <module> print A.getValues(1,1) AttributeError: 'Matrix' object has no attribute 'getValues' How would I fix this ? Regards Will