Thanks for the information. On Sat, May 29, 2010 at 01:15:29PM +0000, Hans W. Borchers wrote: > Oliver Kullmann <O.Kullmann <at> swansea.ac.uk> writes: > > > > > Hello, > > > > I couldn't find information on whether the logarithmic integrals > > > > Li_m(x) = integral_0^x log(t)^(-m) dt > > > > for x >= 0 are available in R? > > I saw your request only this weekend. > The first logarithmic integral can be computed using the exponential > integral Ei(x) per > > li(x) = Ei(log(x)) >
I found gsl at http://cran.r-project.org/web/packages/gsl/index.html. > and elliptic integrals are part of the 'gsl' package, so > > library('gsl') > x <- seq(2, 10, by=0.5) > y <- expint_Ei(log(x)) > y > > See e.g. the Handbook of Mathematical Functions for how to reduce higher > logarithmic integrals. However here I wasn't succesful: Going through the chapter http://www.math.ucla.edu/~cbm/aands/page_228.htm I didn't find any mentioning of the higher logarithmic integrals. > Another possibility is to use the Web API of 'keisan', the calculation > library of Casio. > Interesting; but again only li(x). Also a google search on "higher logarithmic integrals", "logarithmic integrals" or "li_n(x)" doesn't reveal anything, so I would be thankful for a hint. Thanks again! Oliver ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
