poly

poly — polynomial definition

Calling sequence

[p]=poly(a,"x", ["flag"])  

Parameters

a : matrix or real number
x : symbolic variable
"flag" : string ("roots", "coeff"), default value is "roots".

Description

If a is a matrix, p is the characteristic polynomial i.e. determinant(x*eye()-a), x being the symbolic variable.

If v is a vector, poly(v,"x",["roots"]) is the polynomial with roots the entries of v and "x" as formal variable. (In this case, roots and poly are inverse functions).

poly(v,"x","coeff") creates the polynomial with symbol "x" and with coefficients the entries of v (v(1) is the constant term of the polynomial). (Here poly and coeff are inverse functions).

s=poly(0,"s") is the seed for defining polynomials with symbol "s".

Examples



s=poly(0,"s");p=1+s+2*s^2;
A=rand(2,2);poly(A,"x")
 
  

See also

coeff, matrices, rational