double * vect(int n);
double ** matrix(int nrow, int ncol);
double *** array3d(int n1, int n2, int n3);
double ** triarray(int n);
double *** triarray3d(int m, int n);
void   chfact(double **A, int p);
double f_max(double *x, int n);
double int_trape(double *f);
double ldexgam(double x,double shape,double scale);
void   Rprintvec(double *x, int len);
void   Rprintmat(double **m, int d1, int d2, int iscol);
double sigmoid(double x);
double sigmoid2(double x);
double sum(double *x, int n);
double sumsquares(double *x, int n);
void   tsolve(double **A, double **B, double **C, int p, int m);
void Uprod(double **A, double *x, double *b, int n);
int grid_len;
double grid_incr;