search for: qbirthday

...work by using logs, however, as in the following version function(n, classes = 365, coincident = 2){ k <- coincident c <- classes if (coincident < 2) return(1) if (coincident > n) return(0) if (n > classes * (coincident - 1)) return(1) eps <- 1e-14 if (qbirthday(1 - eps, classes, coincident) <= n) return(1 - eps) f <- function(p) qbirthday(p, c, k) - n lower <- 0 upper <- min( exp( k * log(n) - (k-1) * log(c) ), 1 ) nmin <- uniroot(f, c(lower, upper), tol = eps) nmin$root } Ken

...at algorithms for determining coincidences. In educational testing, it is interesting to look at cheating via the birthday problem where I can assess the probability of n students having the same test score in a class of size k. I was writing my own code for the b-day problem until I ran into the qbirthday() function, which has solutions for the overflow problems I kept running into. There is no "see also" part of this man page which would reference me to other functions which may prove useful for such problems. But, that doesn't mean they don't exist. I am just not familiar enoug...

I get ties in output from runif() when I generate as few as 10^5 variates and get quite a lot when I generate 10^6. Is this expected?? I haven't seen any duplication with rnorm(10^6), but see varying amounts of duplication using rexp(), rbeta() and rgamma(). I would have thought that there'd be enough precision that one wouldn't get ties until generating samples larger than this..

Hi, I tried to calculate the formula for the birthday problem (the probability that at least two people out of a group of n people share the same birthday) But the factorial-function allows me only to calculate factorials up to 170. So is there a way to push that limit? to solve this formula: (factorial(365) / factorial((365-23))) / (365^23) (n=23)

...x.axis was used. (Related to PR#14550.) ? dataframe[[row,col]] now dispatches on [[ methods for the selected column (spotted by Bill Dunlap). ? sort.int() would strip the class of an object, but leave its object bit set. (Reported by Bill Dunlap.) ? pbirthday() and qbirthday() did not implement the algorithm exactly as given in their reference and so were unnecessarily inaccurate. pbirthday() now solves the approximate formula analytically rather than using uniroot() on a discontinuous function. The description of the problem was inaccur...

...x.axis was used. (Related to PR#14550.) ? dataframe[[row,col]] now dispatches on [[ methods for the selected column (spotted by Bill Dunlap). ? sort.int() would strip the class of an object, but leave its object bit set. (Reported by Bill Dunlap.) ? pbirthday() and qbirthday() did not implement the algorithm exactly as given in their reference and so were unnecessarily inaccurate. pbirthday() now solves the approximate formula analytically rather than using uniroot() on a discontinuous function. The description of the problem was inaccur...

...o gl() runs faster by avoiding calling factor(). o The print() method for object.size() accepts B as well as b as an abbreviation for 'bytes'. o unlink() gains a force argument to work like rm -f and if possible override restrictive permissions. o pbirthday() and qbirthday() now use exact calculations for coincident = 2. o unzip() and unz() connections have been updated with support for more recent Zip64 features (including large file sizes and bzip2 compression, but not UTF-8 file names). unzip() has a new option to restore file times f...

...o gl() runs faster by avoiding calling factor(). o The print() method for object.size() accepts B as well as b as an abbreviation for 'bytes'. o unlink() gains a force argument to work like rm -f and if possible override restrictive permissions. o pbirthday() and qbirthday() now use exact calculations for coincident = 2. o unzip() and unz() connections have been updated with support for more recent Zip64 features (including large file sizes and bzip2 compression, but not UTF-8 file names). unzip() has a new option to restore file times f...

...g called on the device, which in turn resulted in incorrect output for postcript() and pdf() devices. (Reported by Marc Schwartz in discussion of the non-bug PR#7820.) o terms.formula needed to add parentheses to formulae with terms containing '|'. (PR#8462) o pbirthday() and qbirthday() now also work for very improbable events {those you are typically *not* interested in}. o Only source help files starting with an upper- or lower-case letter or digit and extension .Rd or .rd are documented to be processed. This is more liberal in that starting with a digit is now also...

...g called on the device, which in turn resulted in incorrect output for postcript() and pdf() devices. (Reported by Marc Schwartz in discussion of the non-bug PR#7820.) o terms.formula needed to add parentheses to formulae with terms containing '|'. (PR#8462) o pbirthday() and qbirthday() now also work for very improbable events {those you are typically *not* interested in}. o Only source help files starting with an upper- or lower-case letter or digit and extension .Rd or .rd are documented to be processed. This is more liberal in that starting with a digit is now also...