Why does the SUBS command not substitute correctly for a symbolic term of variables?

Why does the SUBS command not substitute correctly for a symbolic term of variables?

SUBS does not replace symbolic terms that contain only multiplication operators.

For example:

» syms r q z s;
f2=(r*q+1)*s;
C = maple('coeff',f2,s,1);
subs(f2,C,'C')

ans =

C*s

however,

» f1=(r*q)*s;
C = maple('coeff',f1,s,1);
subs(f1,C,'C')

ans =

r*q*s

Answer 1

[MathWorks Support Team]

This behavior has been submitted to our development staff as a bug.

As a workaround, you can change the symbolic variables to a string and then perform the SUBS command. You can do this with the CHAR command in the following manner:

The CHAR command in MATLAB creates character arrays. For more information information on how to use the syntax, please refer to the MATLAB User's Guide function reference at the URL below :

https://www.mathworks.com/help/matlab/ref/char.html

f1=(r*q)*s;
C = maple('coeff',f1,s,1);
subs(f1,char(C),'C')

ans =

(C)*s