[R] Lists into matrices within lists...again

[David Winsemius]

On Feb 22, 2010, at 8:27 PM, ewaters wrote:

>
> Related questions to this have been asked before, but I have tried all
> options they gave me unsuccessfully (do.call and unlist).
>
> I start with three lists of summary statistics,  100 elements each,  
> which I
> bind together:
>

None of this represents data that are too large to include in an  
unambiguous fashion with dump or dput. Why do youy persist in asking  
questions whare there remain ambiguities?


> statslist <- as.data.frame(cbind (means, vars, mcrs))
>
> I then take 100 samples of this data frame of varying lengths:
>
> stats <- lapply (1:100, function (dummy) {
> statslist[sample(nrow(statslist), (sample (10:20, 1, replace = TRUE)),
> replace = TRUE),]})

So what are readers supposed to do? Create similar structures and work  
on them?
>
> It returns basically what I want:
>
>> stats[[i]]
>     means      vars        mcrs
> 71    1.81  3.832222     2.92725
> 9     2.56  8.127677    4.734874
> 91    3.44   9.66303     5.24902
> 68    0.14 0.1216162 0.008686869
>
> except that:
>
>> is.list(stats[[i]]$means)
> [1] TRUE

So lapply on a list returns a list? Where is the surprise?
>
> I don't want this to be a list, because I want to do regressions  
> using the
> variable which are in columns, which apparently R won't do if they  
> are in
> lists.
>
> I have tried every possible combination of working with do.call,  
> rbind,
> as.data.frame, etc to get this into matrix form to no avail.
>
> I have also tried using sapply instead of lapply, but that returns  
> vectors
> which again, R doesn't want to do regression on.

????  R does not want to do regressions on vectors??? How can that be?

>
> Any tips would be very much appreciated, been going around in  
> circles for a
> while here.
>

Reproducible data would answer these questions and prevent this  
"circular" process that _you_ are responsible for allowing to continue.

-- 
David.

> Edward Waters
> PhD Student UNSW
>
>
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