Full_Name: Morten Welinder Version: 2.1.0 OS: src only Submission from: (NULL) (216.223.241.212)

Now that pcauchy has been fixed, it is becoming clear that qcauchy suffers from the same problems. qcauchy(pcauchy(1e100,0,1,FALSE,TRUE),0,1,FALSE,TRUE) should yield 1e100 back, but I get 1.633178e+16. The code below does much better. Notes: 1. p need not be finite. -Inf is ok in the log_p case and R_Q_P01_check already checks things. 2. No need to disallow scale=0 and infinite location. 3. The code below uses isnan and finite directly. It needs to be adapted to the R way of doing that. double qcauchy (double p, double location, double scale, int lower_tail, int log_p) { if (isnan(p) || isnan(location) || isnan(scale)) return p + location + scale; R_Q_P01_check(p); if (scale < 0 || !finite(scale)) ML_ERR_return_NAN; if (log_p) { if (p > -1) lower_tail = !lower_tail, p = -expm1 (p); else p = exp (p); } if (lower_tail) scale = -scale; return location + scale / tan(M_PI * p); } ______________________________________________ R-devel@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-devel