powsfr.h File Reference

Definition of a buffer for pre-computed powers of a machine real number. More...

Go to the source code of this file.

Data Structures
struct	powsfr_struct
	The powers of the real number x using machine floating point numbers. More...

Typedefs
typedef powsfr_struct	powsfr_t[1]
	Practical wrapper for powsfr_struct. More...
typedef powsfr_struct *	powsfr
	Convenience pointer to eval_struct.

Functions
powsfr	powsfr_new (deg_t size)
	Returns a new buffer of powers of machine real numbers, with initial storage space for size powers. More...
bool	powsfr_free (powsfr xn)
	Frees all the memory used by the buffer xn, assuming the struct has been allocated with malloc(), for example with powsfr_new(). More...
bool	powsfr_set (powsfr xn, coeff_t x)
	Sets the real number of which the powers will be computed by the buffer xn. More...
coeff_t	powsfr_pow (powsfr xn, deg_t pow)
	Computes x^pow using repeated squares method and the cache of previously computed powers. More...
coeff_t	powsfr_pow_once (powsfr xn, deg_t pow)
	Computes x^pow using repeated squares method and the cache of previously computed powers. More...

Detailed Description

Definition of a buffer for pre-computed powers of a machine real number.

Definition in file powsfr.h.

Typedef Documentation

powsfr_t

typedef powsfr_struct powsfr_t[1]

Practical wrapper for powsfr_struct.

To avoid the constant use * and & the type powsfr_t is a pointer.

Definition at line 56 of file powsfr.h.

Function Documentation

powsfr_free()

bool powsfr_free

(

powsfr

xn

)

Frees all the memory used by the buffer xn, assuming the struct has been allocated with malloc(), for example with powsfr_new().

Parameters

xn	the powers buffer

Returns

true if successfull, false otherwise.

powsfr_new()

powsfr powsfr_new

(

deg_t

size

)

Returns a new buffer of powers of machine real numbers, with initial storage space for size powers.

Warning

size must be at most MAX_DEG.

Parameters

size	the size of the buffer

Returns

the new buffer, NULL if some error occurred.

powsfr_pow()

coeff_t powsfr_pow	(	powsfr	xn,
		deg_t	pow
	)

Computes x^pow using repeated squares method and the cache of previously computed powers.

It caches intermediary powers of x that have been computed to accelerate later calls of this function. Also, if pow is larger than the size of the buffer xn, it is automatically increased to store the result.

Parameters

xn	the powers buffer
pow	the power to compute

Returns

the result x^pow, NaN if some error occurred.

powsfr_pow_once()

coeff_t powsfr_pow_once	(	powsfr	xn,
		deg_t	pow
	)

Computes x^pow using repeated squares method and the cache of previously computed powers.

It does NOT cache intermediary powers of x.

Parameters

xn	the powers buffer
pow	the power to compute

Returns

the result x^pow, NULL if some error occurred.

powsfr_set()

bool powsfr_set	(	powsfr	xn,
		coeff_t	x
	)

Sets the real number of which the powers will be computed by the buffer xn.

Parameters

xn	the powers buffer
x	the real number

Returns

true if successfull, false otherwise.