[R] correlation with boot

[ctu at bigred.unl.edu]

Hi Professor Ripley,
(Thank you very much)^infinite for your response. I still have few questions
1. R shows that I have two column in nlaw data.
> ncol(nlaw)
[1] 2
> corr(nlaw)
[1] 0.7763745
2. Why can't I use boot::corr? I check corr in boot package and it  
seems to be used for computing correlation coefficient,right?
3. The last question, cor is for computed the correlation variance and  
covariance matrix. Would you give a explanation for   
cor(data[ind,])[1,2]
I do not get it.


Appreciate,
Chunhao


Quoting Prof Brian Ripley <ripley at stats.ox.ac.uk>:

> Please look at the help for boot, in particular what it says the form
> of 'statistic' should be.  Possibly what you want is
>
> corr.t <- function(data, ind) cor(data[ind,])[1,2]
>
> nlaw appears to be a single-column matrix: that will not work either.
>
> On Mon, 1 Sep 2008, ctu at bigred.unl.edu wrote:
>
>> Hi R users,
>> I have one simple question but I really don't know why I can't get it work.
>> The data was adopted from Efron's An introduction to the bootstrap book.
>>> nlaw
>>    LSAT  GPA
>> [1,]  576 3.39
>> [2,]  635 3.30
>> [3,]  558 2.81
>> [4,]  578 3.03
>> [5,]  666 3.44
>> [6,]  580 3.07
>> [7,]  555 3.00
>> [8,]  661 3.43
>> [9,]  651 3.36
>> [10,]  605 3.13
>> [11,]  653 3.12
>> [12,]  575 2.74
>> [13,]  545 2.76
>> [14,]  572 2.88
>> [15,]  594 2.96
>>> nlaw<-as.matrix(law[,-1])
>>> corr.t<-function(data){
>> +        return(boot::corr(data))
>> +        }
>>> law.boot<-boot(data=nlaw,statistic=corr.t,R=49)
>> Error in statistic(data, original, ...) : unused argument(s) (1:15)
>>
>> many thanks for the help
>> Chunhao
>>
>> ______________________________________________
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>> 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.
>
> -- 
> Brian D. Ripley,                  ripley at stats.ox.ac.uk
> Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
> University of Oxford,             Tel:  +44 1865 272861 (self)
> 1 South Parks Road,                     +44 1865 272866 (PA)
> Oxford OX1 3TG, UK                Fax:  +44 1865 272595