>>>>> mark chappell via R-devel >>>>> on Wed, 9 Jan 2019 13:10:26 +1100 writes:
> Hi I believe the dt() function in stats has small areas of > inaccuracy. > SmallRangeMostDetaileddf150.png shows this occurring in > the 10-11th decimal place. > MyD4 is computed using Myt_NC(), at the bottom of BugL.R - > my function is very slow due to using mpfr, but i believe > accurate to the accuracy of genhypergeo() which it uses - > 14-15 dp. > LargeRangeDiffdf150.png, which is difference between dt() > and my function, shows spikes across -1.5 < x < 1.5. > I assumed probably only a problem for large df, but > SmallRangeCloseZerodf20.png, shows actually more of a > problem with > df = 20. Accuracy seems to be only to 6 decimal places. We did not get a single piece of R code. Maybe you've wanted to attach the 'BugL.R' R script mentioned above, but failed to use 'text/plain' MIME encoding? Note: If this is about using *non*central t-distribution (as the above "NC" suggests), then this is *not* a bug per se, as the help page *does* mention that the acuracy there is reduced. Still, I have created an R bugzilla account for you to report there, i.e., https://bugs.r-project.org/ Best, Martin > Using R version 3.5.2. > Cheers > Mark > [DELETED ATTACHMENT SmallRangeMostDetaileddf150.png, PNG image] > [DELETED ATTACHMENT LargeRangeDiffdf150.png, PNG image] > [DELETED ATTACHMENT SmallRangeCloseZerodf20.png, PNG image] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel