R help - Jul 2010 - How do I get rid of list elements where the value is NULL before applying rbind?

Here is the function that makes the data.frames in the list:

funweek <- function(df)
  if (length(df$elapsed_time) > 5) {
    res = fitdist(df$elapsed_time,"exp")
    year = df$sale_year[1]
    sample = df$sale_week[1]
    mid = df$m_id[1]
    estimate = res$estimate
    sd = res$sd
    samplesize = res$n
    loglik = res$loglik
    aic = res$aic
    bic = res$bic
    chisq = res$chisq
    chisqpvalue = res$chisqpvalue
    chisqdf = res$chisqdf
    if (!is.null(estimate) && !is.null(sd) && !is.null(loglik)
&&
!is.null(aic) && !is.null(bic) &&
        !is.null(chisq) && !is.null(chisqpvalue) &&
!is.null(chisqdf)) {
      rv
data.frame(mid,year,sample,samplesize,estimate,sd,loglik,aic,bic,chisq,chisqpvalue,chisqdf)
      rv
    }
  }

I use the following, with different data, successfully:

z <-
lapply(split(moreinfo,list(moreinfo$m_id,moreinfo$sale_year,moreinfo$sale_week),drop
= TRUE), funweek)
qqq <- z[, c('mid', 'year', 'sample',
'samplesize', 'estimate', 'sd',
'loglik', 'aic','bic', 'chisq',
'chisqpvalue', 'chisqdf')]
ndf2 <- do.call(rbind, qqq)


However, I am now getting the following error:
> qqq <- z[, c('mid', 'year', 'sample',
'samplesize', 'estimate', 'sd',
> 'loglik', 'aic','bic', 'chisq',
'chisqpvalue', 'chisqdf')]
> Error in z[, c("mid", "year", "sample",
"samplesize", "estimate", "sd",  :
>   incorrect number of dimensions
>

My suspicion is that it is due to the fact that sometimes one or more of the
elements in my conditional block is null, so nothing is returned and that
this puts a null element into z.  Here is a selection of a couple elements
so you can see what is in 'z'.

$`353.2010.0`
>      mid year sample samplesize   estimate         sd   loglik      aic
> rate 353 2010      0         17 0.06463837 0.01567335 -63.5621 129.1242
>           bic    chisq chisqpvalue chisqdf
> rate 129.9574 14.90239 0.001901994       3
>
> $`355.2010.0`
> NULL
>
> $`376.2010.0`
>      mid year sample samplesize   estimate         sd    loglik      aic
> rate 376 2010      0          6 0.07228863 0.02950606 -21.76253 45.52506
>           bic    chisq  chisqpvalue chisqdf
> rate 45.31682 16.46848 4.946565e-05       1
>
You see the value for rowname = `355.2010.0` is NULL., and it is my guess
that this leads to the error I show above.  But I can't confirm that yet,
because I don't yet know how to get rid of rows that have a row name but
only NULL as the value.

I haven't seen this dealt with in the references I have read so far.

I think I may be able to deal with it by creating dummy values for the
fields the data frame requires, and then use SQL to remove them, but I'd
rather not have to resort to that if I can avoid it.

I can't believe there isn't something in the base package for R that
would
easily handle this, but not knowing the name of the function to look at, I
haven't found it yet.

Any information would be appreciated.

Thanks

Ted

	[[alternative HTML version deleted]]

Here is a function I use to return the non-NULL elements of a list:

 delete.NULLs  <-  function (x.list)
{
    x.list[unlist(lapply(x.list, length) != 0)]
}


On Thu, Jul 22, 2010 at 2:22 PM, Ted Byers <r.ted.byers at gmail.com>
wrote:
> Here is the function that makes the data.frames in the list:
>
> funweek <- function(df)
> ?if (length(df$elapsed_time) > 5) {
> ? ?res = fitdist(df$elapsed_time,"exp")
> ? ?year = df$sale_year[1]
> ? ?sample = df$sale_week[1]
> ? ?mid = df$m_id[1]
> ? ?estimate = res$estimate
> ? ?sd = res$sd
> ? ?samplesize = res$n
> ? ?loglik = res$loglik
> ? ?aic = res$aic
> ? ?bic = res$bic
> ? ?chisq = res$chisq
> ? ?chisqpvalue = res$chisqpvalue
> ? ?chisqdf = res$chisqdf
> ? ?if (!is.null(estimate) && !is.null(sd) &&
!is.null(loglik) &&
> !is.null(aic) && !is.null(bic) &&
> ? ? ? ?!is.null(chisq) && !is.null(chisqpvalue) &&
!is.null(chisqdf)) {
> ? ? ?rv >
data.frame(mid,year,sample,samplesize,estimate,sd,loglik,aic,bic,chisq,chisqpvalue,chisqdf)
> ? ? ?rv
> ? ?}
> ?}
>
> I use the following, with different data, successfully:
>
> z <-
>
lapply(split(moreinfo,list(moreinfo$m_id,moreinfo$sale_year,moreinfo$sale_week),drop
> = TRUE), funweek)
> qqq <- z[, c('mid', 'year', 'sample',
'samplesize', 'estimate', 'sd',
> 'loglik', 'aic','bic', 'chisq',
'chisqpvalue', 'chisqdf')]
> ndf2 <- do.call(rbind, qqq)
>
>
> However, I am now getting the following error:
>
>> qqq <- z[, c('mid', 'year', 'sample',
'samplesize', 'estimate', 'sd',
>> 'loglik', 'aic','bic', 'chisq',
'chisqpvalue', 'chisqdf')]
>> Error in z[, c("mid", "year", "sample",
"samplesize", "estimate", "sd", ?:
>> ? incorrect number of dimensions
>>
>
>
> My suspicion is that it is due to the fact that sometimes one or more of
the
> elements in my conditional block is null, so nothing is returned and that
> this puts a null element into z. ?Here is a selection of a couple elements
> so you can see what is in 'z'.
>
> $`353.2010.0`
>> ? ? ?mid year sample samplesize ? estimate ? ? ? ? sd ? loglik ? ? ?aic
>> rate 353 2010 ? ? ?0 ? ? ? ? 17 0.06463837 0.01567335 -63.5621 129.1242
>> ? ? ? ? ? bic ? ?chisq chisqpvalue chisqdf
>> rate 129.9574 14.90239 0.001901994 ? ? ? 3
>>
>> $`355.2010.0`
>> NULL
>>
>> $`376.2010.0`
>> ? ? ?mid year sample samplesize ? estimate ? ? ? ? sd ? ?loglik ? ?
?aic
>> rate 376 2010 ? ? ?0 ? ? ? ? ?6 0.07228863 0.02950606 -21.76253
45.52506
>> ? ? ? ? ? bic ? ?chisq ?chisqpvalue chisqdf
>> rate 45.31682 16.46848 4.946565e-05 ? ? ? 1
>>
>
> You see the value for rowname = `355.2010.0` is NULL., and it is my guess
> that this leads to the error I show above. ?But I can't confirm that
yet,
> because I don't yet know how to get rid of rows that have a row name
but
> only NULL as the value.
>
> I haven't seen this dealt with in the references I have read so far.
>
> I think I may be able to deal with it by creating dummy values for the
> fields the data frame requires, and then use SQL to remove them, but
I'd
> rather not have to resort to that if I can avoid it.
>
> I can't believe there isn't something in the base package for R
that would
> easily handle this, but not knowing the name of the function to look at, I
> haven't found it yet.
>
> Any information would be appreciated.
>
> Thanks
>
> Ted
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

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