extern float betacf(float a, float b, float x);
extern float betai(float a, float b, float x);
extern void  fit(float *x, float *y, int ndata, float *sig, int mwt, float *a,
				 float *b, float *siga, float *sigb, float *chi2, float *q);
extern void  fpoly(float x, float *p, int np);
extern float gammln(float xx);
extern float gammq(float a, float x);
extern float gasdev(int *idum);
extern void  gcf(float *gammcf, float a, float x, float *gln);
extern void  gser(float *gamser, float a, float x, float *gln);
extern void  ludcmp(double **a, int n, double *d);
extern void  medfit(float *x, float *y, int ndata, float *a, float *b,
					float *abdev);
extern void  pearsn(float *x, float *y, int n, float *r, float *prob, float *z);
extern float ran1(int *idum);
extern float rofunc(float b);
extern void  sort(int n, float *ra);
extern void  spline(float *x, float *y, int n, float yp1, float ypn, float *y2);
extern void  splint(float *xa, float *ya, float *y2a, int n, float x, float *y);
extern void  svdcmp(float **a, int m, int n, float *w, float**v);
extern void  svbksb(float **u, float *w, float **v, int m, int n, float *b, float *x);
extern void  svdfit(float *x, float *y, float *sig, int ndata, float *a,
			 int ma, float **u, float **v, float *w, float *chisq,
			 void (*funcs)(float x, float *afunc, int ma));
extern float Gyrater(float *y, int n, int lag, int edim);
extern float Gyratsvd(float **y, int n, int edim);
extern float Square(float x);