mathmisc.h File Reference

Macros
#define	sinc(x)   ((x)!=0?(sin(M_PI*x)/(M_PI*x)):1)
#define	mysqrt(A)   (A<0?-sqrt(-A):sqrt(A))

Typedefs
typedef real(*	golden_section_fun) (void *param, real x)

Functions
long double	factorial (long n1, long n2)
long *	invperm (long *p, long np)
void	maxminlong (const long *__restrict p, long N, long *__restrict max, long *__restrict min)
long	nextpow2 (long n)
long	nextfftsize (long n)
unsigned long	mylog2 (unsigned long n)
real	golden_section_search (golden_section_fun f, void *param, real x1, real x4, real tau)
spint *	readspint (file_t *fp, long *nx, long *ny)
int	readvec (void *p, uint32_t magic_p, uint32_t magic_file, size_t size, size_t nmemb, file_t *fp)

Detailed Description

A few math routines

Function Documentation

factorial()

long double factorial	(	long	n1,
		long	n2
	)

Compute the factorial from n1 to n2. Overflow LONG if n2>20, so we use double as output.

invperm()

long* invperm	(	long *	p,
		long	np
	)

Reverse an permution vector. A=B(p) <==> A(pi)=B

maxminlong()

void maxminlong	(	const long *__restrict	p,
		long	N,
		long *__restrict	max,
		long *__restrict	min
	)

Compute max, min and sum of a long vector

nextpow2()

long nextpow2

(

long

n

)

Find the next number that is power of 2.

nextfftsize()

long nextfftsize

(

long

n

)

Find the next number suitable for FFT. Use radix of 2, 3, 5, 7, 11

readspint()

spint* readspint	(	file_t *	fp,
		long *	nx,
		long *	ny
	)

Read spint array of size nx*ny from file and do optional data conversion.

readvec()

int readvec	(	void *	p,
		uint32_t	magic_p,
		uint32_t	magic_file,
		size_t	size,
		size_t	nmemb,
		file_t *	fp
	)

Read a vector from file and perform conversion if type mismatches.