Replace powers with a sequence

Hello friends!

Consider a binomial symbolic expression like (x-1)^3 and a symbolic vector e of size 3 (e=sym('e',[1 3]) ). Of

course, in my real problem I have 'n' instead of 3 but I just used 3 here for simplicity. If expand (x-1)^3 then I get

(x-1)^3 = x^3-3*x^3+3*x-1;

which includes all powers of x from 0 to 3, as we know. Now, I need to substitute x with e(1), x^2 with e(2), x^3 with e(3).

Unfortunately, I cannot use 'subs' command here since when I try to assign x with e(1), it automatically assigns x^2 with

e(1)^2 and x^3 with e(1)^3 which is not what I want (similarly, if I try to asign x^2 with e(2) it might interfere with other powers

of x).

Ant idea?

Thanks!

Babak

[Rik]

If by e(k) you mean exp(k), isn't the replacement equivalent to what you want? It might not look tidy, but it is the same number.

[Mohammad Shojaei Arani]

No. I do not mean exp. 'e' is just a symbolic array. If you look at the title of mt post "Replace powers with asequence" you will see that I am not cconsidering a specific sequence.

Answer 1

[Torsten]

syms x

c = sym2poly(expand((x-1)^3));

e = sym('e',[3,1]);

c_times_e = c*e