[R] help please. 2 tables, which test?

[Greg Snow]

Just what null hypothesis are you trying to test or what question are
you trying to answer by comparing 2 matrices of different size?

I think you need to figure out what your real question is before
worrying about which test might work on it.

Trying to get your data to fit a given test rather than finding the
appropriate test or other procedure to answer your question is like
buying a new suit then having plastic surgery to make you fit the suit
rather than having the tailor modify the suit to fit you.

If you can give us more information about what your question is we
have a better chance of actually helping you.

On Fri, Mar 9, 2012 at 9:46 AM, aoife doherty <aaral.singh at gmail.com> wrote:
>
> Thank you. Can the chi-squared test compare two matrices that are not the
> same size, eg if matrix 1 is a 2 X 4 table, and matrix 2 is a 3 X 5 matrix?
>
>
>
> On Fri, Mar 9, 2012 at 4:37 PM, Greg Snow <538280 at gmail.com> wrote:
>>
>> The chi-squared test is one option (and seems reasonable to me if it
>> the the proportions/patterns that you want to test).  One way to do
>> the test is to combine your 2 matrices into a 3 dimensional array (the
>> abind package may help here) and test using the loglin function.
>>
>> On Thu, Mar 8, 2012 at 5:46 AM, aaral singh <aaral.singh at gmail.com> wrote:
>> > Hi.Please help if someone can.
>> >
>> > Problem:
>> > I have 2 matrices
>> >
>> > Eg
>> >
>> > matrix 1:
>> >                Freq  None  Some
>> >  Heavy    3        2          5
>> >  Never    8       13         8
>> >  Occas    1        4          4
>> >  Regul     9        5         7
>> >
>> > matrix 2:
>> >                  Freq     None     Some
>> >  Heavy        7          1             3
>> >  Never      87         18          84
>> >  Occas      12           3            4
>> >  Regul        9            1            7
>> >
>> >
>> > I want to see if matrix 1 is significantly different from matrix 2. I
>> > consider using a chi-squared test. Is this appropriate?
>> > Could anyone advise?
>> > Many thank you.
>> > Aaral Singh
>> >
>> > --
>> > View this message in context:
>> > http://r.789695.n4.nabble.com/help-please-2-tables-which-test-tp4456312p4456312.html
>> > Sent from the R help mailing list archive at Nabble.com.
>> >
>> > ______________________________________________
>> > R-help at 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.
>>
>>
>>
>> --
>> Gregory (Greg) L. Snow Ph.D.
>> 538280 at gmail.com
>>
>> ______________________________________________
>> R-help at 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.
>
>



-- 
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com