list values in symbolic function, a simplification problem

Dear all,

I have a Matlab function fct.m that returns a symbolic function. Inside the fct.m file, I create a vector, say

    A = [1 2 3 4];

Then I declare

    syms x y;
    f = sym('A(1)+A(2)*x+A(3)*x+A(4)*x*y');

and I return f as the output of fct.m .

The problem I have now is that I obtain in the command window

f =
A(1)+A(2)*x+A(3)*x+A(4)*x*y

However, I would like to know what the A(1), ..., A(4) are and subsequently use Matlab to simplify f. However, Matlab does not seem to understand that A(1), ..., A(4) are actual numbers. As an example I would like to see

f = 
1 + 2*x + 3*x + 5*x*y

and get f = 1 + 5*x*(1+y) after simplification.

I would appreciate any help with this. Obviously the A(i)'s are not given by me, but rather computed with another function call.

Thanks in advance,

dodo

Answer 1

[Azzi Abdelmalek]

Why to not write it like:

A = [1 2 3 4];
syms x y;
f = A(1)+A(2)*x+A(3)*x+A(4)*x*y

Answer 2

[Adrian Szatmari]

Thanks, yes I figured out that this actually works, instead of giving a function as an output, just give the vector as the output, and then write a script instead of a Matlab function.