The R Project SVN R

    /* Utilities for `dpq' handling (density/probability/quantile) */

/* give_log in "d";  log_p in "p" & "q" : */
#define give_log log_p
                            /* "DEFAULT" */
                            /* --------- */
#define R_D__0  (log_p ? ML_NEGINF : 0.)        /* 0 */
#define R_D__1  (log_p ? 0. : 1.)           /* 1 */
#define R_DT_0  (lower_tail ? R_D__0 : R_D__1)      /* 0 */
#define R_DT_1  (lower_tail ? R_D__1 : R_D__0)      /* 1 */

#define R_D_Lval(p) (lower_tail ? (p) : (1 - (p)))  /*  p  */
#define R_D_Cval(p) (lower_tail ? (1 - (p)) : (p))  /*  1 - p */

#define R_D_val(x)  (log_p  ? log(x) : (x))     /*  x  in pF(x,..) */
#define R_D_qIv(p)  (log_p  ? exp(p) : (p))     /*  p  in qF(p,..) */
#define R_D_exp(x)  (log_p  ?  (x)   : exp(x))  /* exp(x) */
#define R_D_log(p)  (log_p  ?  (p)   : log(p))  /* log(p) */
#define R_D_Clog(p) (log_p  ? log1p(-(p)) : (1 - (p)))/* [log](1-p) */

/* log(1-exp(x)):  R_D_LExp(x) == (log1p(- R_D_qIv(x))) but even more stable:*/
#define R_D_LExp(x)     (log_p ? \
                           ((x) > -M_LN2 ? log(-expm1(x)) : log1p(-exp(x))) : \
             log1p(-x))
/*till 1.8.x:
 * #define R_DT_val(x)  R_D_val(R_D_Lval(x))
 * #define R_DT_Cval(x) R_D_val(R_D_Cval(x)) */
#define R_DT_val(x) (lower_tail ? R_D_val(x)  : R_D_Clog(x))
#define R_DT_Cval(x)    (lower_tail ? R_D_Clog(x) : R_D_val(x))

/*#define R_DT_qIv(p)   R_D_Lval(R_D_qIv(p))         *  p  in qF ! */
#define R_DT_qIv(p) (log_p ? (lower_tail ? exp(p) : - expm1(p)) \
                   : R_D_Lval(p))

/*#define R_DT_CIv(p)   R_D_Cval(R_D_qIv(p))         *  1 - p in qF */
#define R_DT_CIv(p) (log_p ? (lower_tail ? -expm1(p) : exp(p)) \
                   : R_D_Cval(p))

#define R_DT_exp(x) R_D_exp(R_D_Lval(x))        /* exp(x) */
#define R_DT_Cexp(x)    R_D_exp(R_D_Cval(x))        /* exp(1 - x) */

#define R_DT_log(p) (lower_tail? R_D_log(p) : R_D_LExp(p))/* log(p) in qF */
#define R_DT_Clog(p)    (lower_tail? R_D_LExp(p): R_D_log(p))/* log(1-p) in qF*/

#define R_Q_P01_check(p)            \
    if ((log_p  && p > 0) ||            \
    (!log_p && (p < 0 || p > 1)) )      \
    ML_ERR_return_NAN


/* additions for density functions (C.Loader) */
#define R_D_fexp(f,x)     (give_log ? -0.5*log(f)+(x) : exp(x)/sqrt(f))
#define R_D_forceint(x)   floor((x) + 0.5)
#define R_D_nonint(x)     (fabs((x) - floor((x)+0.5)) > 1e-7)
#define R_D_notnnegint(x) (x < 0. || R_D_nonint(x))

#define R_D_nonint_check(x)                 \
   if(R_D_nonint(x)) {                  \
    MATHLIB_WARNING("non-integer x = %f", x);   \
    return R_D__0;                  \
   }