Using matrix elements as arguments
I have a rather easy question, or so it would seem. I have looked for an answer but was unable to find one anywhere so I'm asking it here.
I am making a very simple iterative algorithm for which the input as well as the output at the end of every iteration is a vector (or matrix for that matter). What I want to do is use these elements as arguments for several functions during each of the iteration. So for example
x=var('x') y=var('y') z=matrix(2,1,[ , ] f=x^2+y^3 H=f.hessian()
Then what I would like to do is say
But no matter what I try I can't seem to get it to work. Ideas?