void svdfit(double x[], double y[], double sig[], int ndata, double a[], int ma,
	double **u, double **v, double w[], double *chisq,
	void (*funcs)(double, double [], int));
double pythag(double a, double b);
void svbksb(double **u, double w[], double **v, int m, int n, double b[], double x[]);
void svdcmp(double **a, int m, int n, double w[], double **v);
void svdvar(double **v, int ma, double w[], double **cvm);

void nrerror(char error_text[]);

double *vector(long size);
void free_vector(double *v);
int *ivector(long size);
void free_ivector(int *v);
double **matrix(long rows, long cols);
void free_matrix(double **m);

static double value;
#define POW(value)((value)*(value)) 
static double maxarg1,maxarg2;
#define FMAX(a,b) (maxarg1=(a),maxarg2=(b),(maxarg1) > (maxarg2) ?\
        (maxarg1) : (maxarg2))
static int iminarg1,iminarg2;
#define IMIN(a,b) (iminarg1=(a),iminarg2=(b),(iminarg1) < (iminarg2) ?\
        (iminarg1) : (iminarg2))

#define SIGN(a,b) ((b) >= 0.0 ? fabs(a) : -fabs(a))