poly

Arguments

a

matrix or real number

vname

String, the symbolic variable name. If the string have more than 4 characters only the first 4 are taken into account.

"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). Note that Infinite roots gives zero highest degree coefficients.

• 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")
//rational fractions
h=(1+2*%s)/poly(1:4,'s','c')

See Also

• coeff
• roots
• varn
• horner
• derivat
• matrices
• rational