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See the recommended documentation of this function

Scilab help >> Scilab > poly

# 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')```

• 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