MATLAB: Removing exponents from a sysm class term

mupadSymbolic Math Toolboxsyms

I am interested in removing the exponents from a syms class object. For instance, i wish the following expression,

answer = x^2 + y^2*z^2

to instead take the form of,

answer = x + y*z

I was wondering if there was a shorter way to do this other than writing my own muPad procedure.

Thanks in advance.

Ross Montgomery

You can use evalin to do a substitution of the powers inside MuPAD:

 >> evalin(symengine, ['subs(', char(answer) ,', hold(_power) = (x->x), EvalChanges)'])
 ans =
 x + y*z

y = evalin(symengine, 'x+1')

which does the same thing as

y = sym('x+1')

except that going through sym() has more overhead for this situation and will give you the warning.

Caution: when you use

syms x
sym('x+1')

then the x of the second version does not necessarily refer to the same thing that the first one refers to. For example if you had used

syms x y
x = y + 2
sym('x+1')

then you will not get y + 3

Yes. Both the MuPad symbolic engine and the "mupad" notebook interface still exist.