beschb.c

来自「可以用于科学计算的库」· C语言 代码 · 共 26 行

#define NUSE1 5
#define NUSE2 5

void beschb(double x, double *gam1, double *gam2, double *gampl, double *gammi)
{
	float chebev(float a, float b, float c[], int m, float x);
	float xx;
	static float c1[] = {
		-1.142022680371168e0,6.5165112670737e-3,
		3.087090173086e-4,-3.4706269649e-6,6.9437664e-9,
		3.67795e-11,-1.356e-13};
	static float c2[] = {
		1.843740587300905e0,-7.68528408447867e-2,
		1.2719271366546e-3,-4.9717367042e-6,-3.31261198e-8,
		2.423096e-10,-1.702e-13,-1.49e-15};

	xx=8.0*x*x-1.0;
	*gam1=chebev(-1.0,1.0,c1,NUSE1,xx);
	*gam2=chebev(-1.0,1.0,c2,NUSE2,xx);
	*gampl= *gam2-x*(*gam1);
	*gammi= *gam2+x*(*gam1);
}
#undef NUSE1
#undef NUSE2