`coeffs`

Coefficients of a polynomial in one or more variables.

Category: Mathematics > Formula Manipulation and Simplification

Syntax

c = coeffs(p, x)

Returns the coefficients of p as a polynomial in x, lowest power first.

[c, t] = coeffs(p, x)

Also returns the terms t that each coefficient multiplies.

Description

coeffs first expands p and then collects the terms by power of x. Terms with a zero coefficient are skipped, which is why the second output is useful: it says which power each coefficient belongs to. Coefficients that depend on other symbols stay symbolic.

Input arguments

p: Symbolic polynomial expression.
x: Variable (or vector of variables) of the polynomial.

Output arguments

c: Row vector of coefficients; they may contain the other symbols.
t: Row vector of the powers of x matching c.

Example

Coefficients with their terms

syms x
[c, t] = coeffs(3*x^2 + 2*x + 1, x)
coeffs(x^3 + 2*x, x)

Output

c = 
[1, 2, 3]
t = 
[1, x, x^2]
ans = 
[2, 1]

Notes

Only the single-variable form with an explicit variable was checked in MatLivre; the multivariable form with a vector of variables is not supported.

coeffs