[R] Help to find correlation.

[Martin Henry H. Stevens]

Hi,
See help files for read.csv for input.
See help files for cor.test
dat <- read.csv("whatever-your-file-is", other info...)

# Generate an upper triangular  matrix of Pearson product moment  
correlation coefficients
r.s <- matrix(NA, nr=dim(dat)[2], nc=dim(dat)[2])
rownames(r.s) <- names(dat)
colnames(r.s) <- names(dat)
for(i in 1:(dim(dat)[2]-1)) {
   for(j in i:dim(dat)[2]) r.s[i,j] <- {cor.test(dat[,i], dat[,j]) 
$p.value}}
r.s

# Generate an upper triangular  matrix of P values of the r's
p.s <- matrix(NA, nr=dim(dat)[2], nc=dim(dat)[2])
rownames(p.s) <- names(dat)
colnames(p.s) <- names(dat)
for(i in 1:(dim(dat)[2]-1)) {
   for(j in i:dim(dat)[2]) p.s[i,j] <- {cor.test(dat[,i], dat[,j]) 
$p.value}}
p.s

Please do read the help files.
Hank

On Feb 16, 2006, at 1:17 PM, Anusha Aiyaloo kannan ((RIT Student))  
wrote:

>
> Respected Sir,
>
> I am trying to import excel file into R, but I need to truncate  
> some columns from the original file.
>
>  How to delete unwanted columns when I import data from excel file.
>
> How to use cor.test for the data when I want the output rowwise.
>
> How to do grouping and use cor.test on that data
>
> I need some help regarding how to calculate the correlation.
> I don't know whether you understood my question, but I need help.
>
> Any help is appreciated.
>
> Thanks,
>
>
>
> 	[[alternative HTML version deleted]]
>
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Dr. Martin Henry H. Stevens, Assistant Professor
338 Pearson Hall
Botany Department
Miami University
Oxford, OH 45056

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