Next: Euclidian division Up: Utilities Previous: Implementation   Contents

## Derivative of a polynomial

The derivatives of a polynomial may be computed using the procedures:
```
VECTOR Derivative_Polynomial_Interval(int Degree,VECTOR &Coeff)
INTEGER_VECTOR Derivative_Polynomial_Interval(int Degree,INTEGER_VECTOR &Coeff);
VECTOR Nth_Derivative_Polynomial_Interval(int Degree,VECTOR &Coeff,int n)
```
These procedures enable to get the coefficients of the first and n-th derivative of a polynomial defined by its REAL or INT coefficients.

Due to rounding errors there may be errors in the coefficients provided by the previous procedures. The procedure:

```
INTERVAL_VECTOR Derivative_Polynomial_Safe_Interval(int Degree,VECTOR &Coeff);
```
will return an INTERVAL_VECTOR (i.e. a set of intervals) which are guaranteed to include the true value of the coefficients of the derivative. A faster procedure may be used if "safe" interval values of the coefficients have been pre-computed:
```
INTERVAL_VECTOR Derivative_Polynomial_Fast_Safe_Interval(int Degree,INTERVAL_VECTOR &Coeff);
```

If we deal with polynomial with interval coefficients the following procedures may be used:

```
INTERVAL_VECTOR Derivative_Polynomial_Interval(int Degree,INTERVAL_VECTOR &Coeff)
INTERVAL_VECTOR Nth_Derivative_Polynomial_Interval(int Degree,
INTERVAL_VECTOR &Coeff,int n)
```

Jean-Pierre Merlet 2012-12-20