2015-01-27 09:22:12 +0100 received badge ● Taxonomist 2015-01-06 00:06:10 +0100 received badge ● Famous Question (source) 2013-10-08 21:17:13 +0100 received badge ● Good Question (source) 2013-06-08 12:10:54 +0100 received badge ● Notable Question (source) 2013-05-26 13:48:03 +0100 received badge ● Nice Question (source) 2012-07-20 18:26:13 +0100 received badge ● Popular Question (source) 2010-11-29 15:47:43 +0100 received badge ● Student (source) 2010-11-26 10:44:53 +0100 asked a question 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,[ [1],[1] ] f=x^2+y^3 H=f.hessian()  Then what I would like to do is say H(z[0],z[1])  or H(z)  But no matter what I try I can't seem to get it to work. Ideas?