# [R] Problem in performing goodness of fit test in R.

(Ted Harding) Ted.Harding at manchester.ac.uk
Sun Feb 14 10:02:03 CET 2010

```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 copy&paste 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.

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Date: 14-Feb-10                                       Time: 09:02:01
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