void C_split(const double *x, int p,

             const double *y, int q,

             const double *weights, int n,

             const int *orderx, SEXP splitctrl, SEXP linexpcov2sample, 

             SEXP expcovinf, double *cutpoint, double *maxstat, 

             double *statistics);

void C_splitcategorical(const int *codingx, int p,

                        const double *y, int q,

                        const double *weights, int n,

                        double *standstat,

                        SEXP splitctrl, SEXP linexpcov2sample, 

                        SEXP expcovinf, double *cutpoint, int *levelset, 

                        double *maxstat, double *statistics);