On 02/12/2013 9:47 AM, Michael Friendly wrote:
I want to generate a collection of probability distributions in a data frame, with varying parameters. There must be some simpler way than what I have below (avoiding rbind and cbind), but I can't quite see it.x <- seq(0,12) bin.df <- as.data.frame( rbind( cbind(x, prob=dbinom(x,12,1/6), p=1/6), cbind(x, prob=dbinom(x,12,1/3), p=1/3), cbind(x, prob=dbinom(x,12,1/2), p=1/2), cbind(x, prob=dbinom(x,12,2/3), p=2/3) )) bin.df$p <- factor(bin.df$p, labels=c("1/6", "1/3", "1/2", "2/3")) str(bin.df) > str(bin.df) 'data.frame': 52 obs. of 3 variables: $ x : num 0 1 2 3 4 5 6 7 8 9 ... $ prob: num 0.1122 0.2692 0.2961 0.1974 0.0888 ... $ p : Factor w/ 4 levels "1/6","1/3","1/2",..: 1 1 1 1 1 1 1 1 1 1 ... >
dbinom can take vector inputs for the parameters, so this would be a bit simpler:
x <- seq(0,12) x <- rep(x, 4) p <- rep(c(1/6, 1/3, 1/2, 2/3), each=13) bin.df <- data.frame(x, prob = dbinom(x, 12, p), p) Duncan Murdoch ______________________________________________ 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.
