[symbolic] How to get the equation component?

Hi, I using mlx document to do my symbolic calculation. Just wonder how to access equation's component?

That is, sigma_1 in the image attached.

Many thanks

Sendy

[Nicolas Schmit]

Please post the code generating the symbolic equation.

Answer 1

[Walter Roberson]

[s1_c, s1_p] = coeffs(B2ch, sigma_1);

Now s1_c will be a vector of coefficients of sigma_1 in B2, and s1_p will be the corresponding powers of sigma_1. Only the powers that are used will be present. For example for

B21 = r1^3 + (-2*r2*r3 + sigma_1^2*i)*r1 + r2*sigma_1 + 2*r3
[s1_c,s1_p] = coeffs((B21+r3*2)/r1,sigma_1)

s1_c =
[ 20, r2/r1, (r1^3 - 2*r2*r3*r1 + 4*r3)/r1]
s1_p =
[ sigma_1^2, sigma_1, 1]

Notice that the 1 might be there -- that is sigma_1^0, the constant term relative to sigma_1