If A is the matrix the answer is 2*(1 - 2^(-A)), which took about 10secs for an example of your size.
>From \sum_{i=1}^n x^{1-i} = (1-x^{-n})/(1-x), E & OE. On Fri, 7 Oct 2005, Tim Smith wrote: > I have a 7000x7000 matrix, and each element is an integer. For each > element, I want to apply the function : > > wt <- 0 > for(q in 1:count){ > wt <- wt + 0.5^(q-1) > } > > I get the value of 'count' from the elements in the matrix , and want to > store the corresponding 'wt' value for that element. > > I suppose I could loop through the matrix, and apply the function to > each element but this would take a really really long time. Are there > any quicker ways to get the same result? -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html