Re: [R] Problem in performing goodness of fit test in R.
On Sun, 2010-02-14 at 12:42 +0500, Faiz Rasool wrote: I am trying to perform goodness of fit test using R. I am using this website http://wiener.math.csi.cuny.edu/Statistics/R/simpleR/stat013.html for help. However, I am unable to carry out the test successfully. My code follows. It is taken from the website just mentioned. freq=c(22,21,22,27,22,36) # frequencies obtained after rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. I just followed instructions on the website. The erorr I receive is erorr in chisq.test(freq,p=prob)/6 probabilities must sum to 1 I am very new to R, so any help would be appreciated. Faiz. Faiz, Well ... In my computer( Phenom X4 9650, runing Ubuntu 9.10 and R 2.10.1) the script work freq=c(22,21,22,27,22,36) # frequencies obtained after rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means Chi-squared test for given probabilities data: freq X-squared = 6.72, df = 5, p-value = 0.2423 About the third line You must read ?chisq.test for better know the command, but you execute one chi-square test with uniform probability distribution -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil __ 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.
Re: [R] Problem in performing goodness of fit test in R.
On 14-Feb-10 07:42:12, Faiz Rasool wrote: I am trying to perform goodness of fit test using R. I am using this website http://wiener.math.csi.cuny.edu/Statistics/R/simpleR/stat013.html for help. However, I am unable to carry out the test successfully. My code follows. It is taken from the website just mentioned. freq=c(22,21,22,27,22,36) # frequencies obtained after # rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. # I just followed instructions on the website. The erorr I receive is erorr in chisq.test(freq,p=prob)/6 probabilities must sum to 1 I am very new to R, so any help would be appreciated. Faiz. I suspect that you must have made an error in entering the commands into R. Prime suspect: You did not have 6 1's in p -- for example you may have put prob=c(1,1,1,1,1)/6 (with only five). I copied your code (as trivially reformatted above) straight into R using copypaste with the mouse, with results: freq=c(22,21,22,27,22,36) # frequencies obtained after # rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. #Chi-squared test for given probabilities # data: freq # X-squared = 6.72, df = 5, p-value = 0.2423 # I just followed instructions on the website. So it worked as it should work. Therefore something went wrong when you entered the code. Check your input! Hoping this helps, Ted. E-Mail: (Ted Harding) ted.hard...@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 14-Feb-10 Time: 09:02:01 -- XFMail -- __ 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.
Re: [R] Problem in performing goodness of fit test in R.
Dear Faiz, On Sat, Feb 13, 2010 at 11:42 PM, Faiz Rasool fai...@gmail.com wrote: The erorr I receive is erorr in chisq.test(freq,p=prob)/6 probabilities must sum to 1 This error message seems a little off. It looks like the entire chi squared test was divided by 6. Notice that the /6 occurs *after* the closing parenthesis for the test. As others have noted, it is probably an input problem, but here is another sample of code you could try. ## all of the data is entered directly into the function. x is the data, p are the probabilities. ## the biggest difference is rather than dividing by 6 to make the probabilities sum to 1, the argument rescale.p=T will make sure that they sum to 1 chisq.test(x=c(22,21,22,27,22,36), p=c(1,1,1,1,1,1), rescale.p=T) Chi-squared test for given probabilities data: c(22, 21, 22, 27, 22, 36) X-squared = 6.72, df = 5, p-value = 0.2423 I am very new to R, so any help would be appreciated. Faiz. Best of luck to you! I have found the list to be very helpful and informative. Joshua -- Joshua Wiley Senior in Psychology University of California, Riverside http://www.joshuawiley.com/ [[alternative HTML version deleted]] __ 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.
Re: [R] Problem in performing goodness of fit test in R.
Good that you got it to work somehow! Faiz: can you report the result, exactly as returned by R, of sum(c(1,1,1,1,1,1)/6) - 1 ?? On my Linux with R version 2.10.0 (2009-10-26) this gives 0. (And, by the way, did you really mean to say you were using R 2.1.01? Was this a typing error for R 2.10.1?) Ted. On 14-Feb-10 09:26:00, Faiz Rasool wrote: Hi all, Following Denis's code, I am able to carry out goodness of fit test. However the responses I have received, indicate that the code I mentioned in a prior email was not incorrect. inclusion of rep(1,6)/6 made a difference for me. I am using windows xp and R 2.1.01. Does difference of operating system makes a difference? As without rep(1,6)/6 R would not carry out chisq.test on my computer. The code I got it to work follows. freq=c(22,21,22,27,22,36)#frequencies obtained after rolling the dice 150 times. prob=rep(1,6)/6#change made after Dennis's suggestion. chisq.test(freq,p=prob)#no error message received now. Chi-squared test for given probabilities data: freq X-squared = 6.72, df = 5, p-value = 0.2423 thanks everyone, Faiz. - Original Message - From: Ted Harding ted.hard...@manchester.ac.uk To: R-help@r-project.org Cc: Faiz Rasool fai...@gmail.com Sent: Sunday, February 14, 2010 2:02 PM Subject: RE: [R] Problem in performing goodness of fit test in R. On 14-Feb-10 07:42:12, Faiz Rasool wrote: I am trying to perform goodness of fit test using R. I am using this website http://wiener.math.csi.cuny.edu/Statistics/R/simpleR/stat013.html for help. However, I am unable to carry out the test successfully. My code follows. It is taken from the website just mentioned. freq=c(22,21,22,27,22,36) # frequencies obtained after # rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. # I just followed instructions on the # website. The erorr I receive is erorr in chisq.test(freq,p=prob)/6 probabilities must sum to 1 I am very new to R, so any help would be appreciated. Faiz. I suspect that you must have made an error in entering the commands into R. Prime suspect: You did not have 6 1's in p -- for example you may have put prob=c(1,1,1,1,1)/6 (with only five). I copied your code (as trivially reformatted above) straight into R using copypaste with the mouse, with results: freq=c(22,21,22,27,22,36) # frequencies obtained after # rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. #Chi-squared test for given probabilities # data: freq # X-squared = 6.72, df = 5, p-value = 0.2423 # I just followed instructions on the # website. So it worked as it should work. Therefore something went wrong when you entered the code. Check your input! Hoping this helps, Ted. E-Mail: (Ted Harding) ted.hard...@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 14-Feb-10 Time: 09:02:01 -- XFMail -- E-Mail: (Ted Harding) ted.hard...@manchester.ac.uk Fax-to-email: +44 (0)870 094 0861 Date: 14-Feb-10 Time: 10:53:34 -- XFMail -- __ 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.
[R] Problem in performing goodness of fit test in R.
I am trying to perform goodness of fit test using R. I am using this website http://wiener.math.csi.cuny.edu/Statistics/R/simpleR/stat013.html for help. However, I am unable to carry out the test successfully. My code follows. It is taken from the website just mentioned. freq=c(22,21,22,27,22,36) # frequencies obtained after rolling the dice 150 times. prob=c(1,1,1,1,1,1)/6 # specify expected frequency for each category. chisq.test(freq,p=prob) # I do not know what this line means. I just followed instructions on the website. The erorr I receive is erorr in chisq.test(freq,p=prob)/6 probabilities must sum to 1 I am very new to R, so any help would be appreciated. Faiz. [[alternative HTML version deleted]] __ 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.
