void lfit(double x[], double y[], double sig[], int ndata, double a[],
	int ma, int lista[], int mfit, double **covar, double *chisq,
	void (*funcs)(double,double *,int));
	void covsrt(double **covar, int ma, int ia[], int mfit);
	void gaussj(double **a, int n, double **b, int m);
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))