From: Rory Winston <rory.winston_at_gmail.com>

Date: Fri, 04 Apr 2008 08:43:23 -0700 (PDT)

}

Date: Fri, 04 Apr 2008 08:43:23 -0700 (PDT)

Hi

(If you're wondering, this is a Project Euler question :))

# Calculate the sum of digits in the decimal representation of 2^n

# Only works for smaller values of n

bsum <- function(n) {

s <- 0 e <- floor(log10(2^n)) for (i in seq(e,0,-1)) { s <- s + (((2^n) %/% 10^i) %% 10) } s

}

The above doesnt work, as I am using an integer modulus which has insufficient precision. so I tried to coerce R to produce a full-precision integer and sum the digits of that:

bsum2 <- function(n) {

s <- 0 strn <- formatC(2^n, format="fg") sum(as.numeric(strsplit(strn,"")[[1]]))}

This also doesnt seem to work. Is there another way I can do this in R?
Cheers

Rory

-- View this message in context: http://www.nabble.com/Arbitrary-Precision-Numbers-tp16492549p16492549.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help_at_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.Received on Fri 04 Apr 2008 - 16:55:30 GMT

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