How to calculate correlation coefficient with R?

Question

Possible Duplicate:
correlation matrix in r

I have an excel sheet which has 700 columns and 25 rows. The sample of my file is shown below. I would like to calculate the correlation coefficient between A1 and A700, A2 and A700, A3 and A700 ,A4 and A700 and so on. What is the easiest way to do this with R?

       A1     A2     A3     A4   ---- --- A700

 A    2.7     5       4     34             34
 B    5.67   7.8      6     45            25.6
 C    2.3    -9      12.5   13            2.8
 D    5.6    6       -56    2.5          -66.7
 E    7.8    5       20     6.7          -56.8 
--
--
--
--

1) Did you mean 700 Rows and 25 Columns? 2) If you are doing this in Excel, did you check out the `=CORREL()`? — Siddharth Rout, Jun 23 '12 at 15:25
@JoshuaUlrich Did you understand my question? I don't want to create a matrix. I need to print the correlation coefficients only. Dear friend, please check my accepted answer. I think, this is not a duplicate question. In my case, the number of rows and columns are not equal. — sagar, Jun 24 '12 at 06:38

score 2 · Answer 1 · answered Jun 23 '12 at 13:51

2

Have a look at ?cor.

For example:

m <- matrix(rnorm(100), nrow=10)
cor(m)

Gives you all the correlations.

answered Jun 23 '12 at 13:51

johannes

14,043
5
40
51

score 2 · Accepted Answer · answered Jun 23 '12 at 14:00

2

This might do the trick:

table <- read.xls(file)
x <- table[1:699]
y <- table[700]
cor(x, y)

answered Jun 23 '12 at 14:00

danuker

861
10
26

Thank you very much for your perfect answer. I think, you only understood my question clearly. – sagar Jun 24 '12 at 06:30
3

to be honest, it was a Google search away – danuker Jun 24 '12 at 15:36

How to calculate correlation coefficient with R?

2 Answers2