On 07-Jan-11 16:20:59, zhaoxing731 wrote: > Hello > I want to calculate natural logarithm of sum of combinations > as follow: (R code)
{com_sum=choose(2000000,482)*choose(1000000,118)+ choose(2000000,483)*choose(1000000,117)+...+ choose(2000000,i)*choose(1000000,600-i)+...+ choose(2000000,600)*choose(1000000,0) #calculate the sum result=log(com_sum) #calculate the log of the sum } > But every element of the com_sum is Inf, so I can't get the > result. Thank you in advance > Yours sincerely > ZhaoXing You may find you can usefully adapt the technique I have described in: http://www.zen89632.zen.co.uk/R/FisherTest/extreme_fisher.pdf A somewhat different but closely related problem. Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <ted.hard...@wlandres.net> Fax-to-email: +44 (0)870 094 0861 Date: 07-Jan-11 Time: 17:42:48 ------------------------------ XFMail ------------------------------ ______________________________________________ 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.