poly

polynomial definition

Calling Sequence

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

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 coefficients of matrix polynomial
• roots roots of polynomials
• varn symbolic variable of a polynomial
• horner polynomial/rational evaluation
• derivat rational matrix derivative
• matrices Scilab object, matrices in Scilab
• rational Scilab objects, rational in Scilab