< Can you help me to overlap a histogram and theoretical density curve of poison distribution?> There is more than one Poisson distribution you could possibly overlap but a common choice is the Poisson with parameter = observed mean of the data - in your case, 0.7.
I think the below is somewhat clumsy but it gives one idea how to do it (and r-experts will cheerfully show a better way :) > par(bg = "cornsilk") > > #number of snails, > r <- c(0, 1, 2, 3, 4, 5, 8, 15) > #frequency of r > f <- c(69, 18, 7, 2, 1, 1, 1, 1) > > #a clumsy way to bin the observed values > breakz <- (0:16) - 0.5 > > x <- rep(r,f) > > xbar <- mean(x) > xbar [1] 0.7 > > hist(x, breaks = breakz, + freq = FALSE, + font.main = 6, + col = "lightgray") > > #change lambda to change the Poisson dist > points(x, dpois(x, lambda = xbar), + type = "l", col = 2) > bob -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, January 15, 2004 11:20 AM To: [EMAIL PROTECTED] Subject: [R] how to overlap plots Dear R experts: Can you help me to overlap a histogram and theoretical density curve of poison distribution? for example data like this: The numbers of sanils found in each of 100 sampling quadrats in an area were as follows: number of snails, r 0 1 2 3 4 5 8 15 f=frequency of r 69 18 7 2 1 1 1 1 apparently this is not Poison but near to Poison, How to overlap the theoretical desity curve to the histgram of this data? Thanks in advance! Josh ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html [[alternative HTML version deleted]] ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
