R help - Nov 2009 - row-wise means

I have a dataframe with 3 columns. The first column stores an index. I would
like to calculate the mean of the numbers stored in each of the rest of the
columns.
So,
here is my data matrix:
col1 col2 col3
1 23 34
2 45 56
3 23 56
4 34 68

For each row I would like to calculate the means of the numbers stored in
col2 and col3.
How can this be done in R?
TIA,
Anjan

-- 
============================anjan purkayastha, phd
bioinformatics analyst
whitehead institute for biomedical research
nine cambridge center
cambridge, ma 02142

purkayas [at] wi [dot] mit [dot] edu
703.740.6939

	[[alternative HTML version deleted]]

Tena koe Anjan

?rowMeans
?apply

You'll need to subset your data matrix to exclude the first column
(e.g., yourData[,-1]).

HTH ....

Peter Alspach
> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of ANJAN PURKAYASTHA
> Sent: Thursday, 19 November 2009 11:28 a.m.
> To: r-help at r-project.org
> Subject: [R] row-wise means
> 
> I have a dataframe with 3 columns. The first column stores an 
> index. I would like to calculate the mean of the numbers 
> stored in each of the rest of the columns.
> So,
> here is my data matrix:
> col1 col2 col3
> 1 23 34
> 2 45 56
> 3 23 56
> 4 34 68
> 
> For each row I would like to calculate the means of the 
> numbers stored in
> col2 and col3.
> How can this be done in R?
> TIA,
> Anjan
> 
> --
> ============================> anjan purkayastha, phd
> bioinformatics analyst
> whitehead institute for biomedical research nine cambridge 
> center cambridge, ma 02142
> 
> purkayas [at] wi [dot] mit [dot] edu
> 703.740.6939
> 
> 	[[alternative HTML version deleted]]
> 
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