derivative.hh

`template <class T, int N>`
`derivative(Array< T, N > func, const T delta, int dimension, Array< T, N > & result) -> void`

`template <class T, int N>`
`gradient(const blitz::TinyVector< int, N > & idx, const blitz::TinyVector< T, N > & delta, const Array< T, N > & func) -> blitz::TinyVector< T, N >`

`template <class T>`
`gradient(const blitz::TinyVector< int, 4 > & idx, const blitz::TinyVector< T, 4 > & delta, const Array< T, 4 > & func) -> blitz::TinyVector< T, 4 >`

`template <class T, int N>`
`derivative(const blitz::TinyVector< int, N > & idx, int dimension, const T delta, const Array< T, N > & func) -> T`

`template <class T, int N>`
`derivative(const blitz::TinyVector< int, N > & idx, int idx_min, int idx_max, int dimension, const T delta, const Array< T, N > & func) -> T`

Compute forward differences on the left border. $f'_i = \frac{-f_{i+2} + 4f_{i+1} - 3f_{i}}{2\Delta f}$
Compute backward differences on the right border. $f'_i = \frac{3f_{i} - 4f_{i-1} + f_{i-2}}{2\Delta f}$
Compute central differences in all other points. $f'_i = \frac{f_{i+1} - f_{i-1}}{2\Delta f}$

`template <class T, int N>`
`derivative(Array< T, N > func, const T delta, int dimension) -> Array< T, N >`

`template <class T>`
`gradient(const blitz::TinyVector< int, 3 > & idx, const blitz::TinyVector< T, 3 > & delta, const Array< T, 3 > & func) -> blitz::TinyVector< T, 3 >`