Re: [R] stats tests on large tables

[Rolf Turner]

On 27/08/2008, at 3:52 AM, Richard Emes wrote:


I have a large table of data which i can read in using read.table.
I then want to conduct various tests on the data.

Is there a simple way to conduct these tests by specifying the  
column headers which relate to different conditions of the experiment?


e.g. data1 <- read.table("test.table", header=TRUE)
t.test(test~control, data = data1)

Which doesn't work and results in the error
"Error in t.test.formula(test ~ control, data = data1) :
  grouping factor must have exactly 2 levels"


	with(data1,t.test(test ~ control)) # You do not need to specify the  
method explicitly.


cheers,

Rolf Turner

##
Attention:\ This e-mail message is privileged and confid...{{dropped:9}}

__
R-help@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.

Re: [R] stats tests on large tables

[John Kane]

Try
t.test(data1[,1],data1[,2]) 
for the first two columns of data1.




--- On Tue, 8/26/08, Richard Emes <[EMAIL PROTECTED]> wrote:

> From: Richard Emes <[EMAIL PROTECTED]>
> Subject: [R] stats tests on large tables
> To: r-help@r-project.org
> Received: Tuesday, August 26, 2008, 11:52 AM
> I have a large table of data which i can read in using
> read.table. 
> I then want to conduct various tests on the data.
> 
> Is there a simple way to conduct these tests by specifying
> the column headers which relate to different conditions of
> the experiment?
> 
> e.g. data1 <- read.table("test.table",
> header=TRUE)
> t.test(test~control, data = data1)
> 
> Which doesn't work and results in the error
> "Error in t.test.formula(test ~ control, data = data1)
> : 
>   grouping factor must have exactly 2 levels"
> 
> 
> Many Thanks
> 
> Richard
>   [[alternative HTML version deleted]]
> 
> __
> R-help@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.


  __
[[elided Yahoo spam]]

__
R-help@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.

[R] stats tests on large tables

[Richard Emes]

I have a large table of data which i can read in using read.table. 
I then want to conduct various tests on the data.

Is there a simple way to conduct these tests by specifying the column headers 
which relate to different conditions of the experiment?

e.g. data1 <- read.table("test.table", header=TRUE)
t.test(test~control, data = data1)

Which doesn't work and results in the error
"Error in t.test.formula(test ~ control, data = data1) : 
  grouping factor must have exactly 2 levels"


Many Thanks

Richard
[[alternative HTML version deleted]]

__
R-help@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.