Matlab - Extract coefficients from polynomial string

Question

I have a string describing a polynomial and would like to extract its coefficients

I'm currently using the following code:

p = 'x^8 + x^4 + x^3 + x^2 + 1';
c = coeffs(sym(p), 'all');

which gives the expected output

c = [1, 0, 0, 0, 1, 1, 1, 0, 1]

however using sym in this way raises the warning: Support of strings that are not valid variable names or define a number will be removed in a future release. To create symbolic expressions, first create symbolic variables and then use operations on them.

I can supress this warning but would like to find an alternative that won't be deprecated in the future. What other approaches are available?

Answer 1

Isn't it simply by declaring at the beginning of your code : syms p instead of giving to Matlab a "last minute discovery" when you use sym(p), making it nervous and reacting in this way ?