On Jul 27, 2011, at 7:44 PM, Gene Leynes wrote:
> David,
>
> Thanks for the suggestion, but I think your answer only works
> because I was printing the wrong thing (because apply with margin=1
> transposes the results,
And if you want to change that, then the t() function is readily at
hand.
> something I always forget).
>
> Check this to see what I mean:
> str(answerGood)
> str(answerBad)
>
> Adding "as.matrix" is interesting and almost does it,
"It" ... What is "it"? In a natural language, ... English preferably.
--
david.
> however the results are still transposed.
>
> Sorry to be confusing with the initial example.
>
> Here's an updated example (adding as.matrix doesn't make a difference)
>
>
> ## Make three example matricies
> exampGood = lapply(2:4, function(x)matrix(rnorm(1000*x),ncol=x))
> exampBad = lapply(1:3, function(x)matrix(rnorm(1000*x),ncol=x))
> ## Two ways to see what was created:
> for(k in 1:length(exampGood)) print(dim(exampGood[[k]]))
> for(k in 1:length(exampBad)) print(dim(exampBad[[k]]))
>
> ## Take the cumsum of each row of each matrix
> answerGood = lapply(exampGood, function(x) apply(x ,1,cumsum))
> answerBad = lapply(exampBad, function(x) apply(x ,1,cumsum))
> answerProposed = lapply(exampBad, function(x) as.matrix(apply(x ,
> 1:1,cumsum)))
> str(answerGood)
> str(answerBad)
> str(answerProposed)
>
> ## Take the first element of the final column of each answer
> for(mat in answerGood){
> mat = t(mat) ## To get back to 1000 rows
> LastColumn = ncol(mat)
> print(mat[2,LastColumn])
> }
> for(mat in answerBad){
> mat = t(mat) ## To get back to 1000 rows
> LastColumn = ncol(mat)
> print(mat[2,LastColumn])
> }
> for(mat in answerProposed){
> mat = t(mat) ## To get back to 1000 rows
> LastColumn = ncol(mat)
> print(mat[2,LastColumn])
> }
>
>
>
> On Wed, Jul 27, 2011 at 5:45 PM, David Winsemius <dwinsem...@comcast.net
> > wrote:
>
> On Jul 27, 2011, at 6:22 PM, Gene Leynes wrote:
>
> I have tried a lot of ways around this, but I can't find a way to
> make apply
> work in a generalized way because it causes a failure whenever
> reduces the
> dimensions of its output.
> The following example is easier to understand than the question.
>
> I wish it had a "drop=TRUE/FALSE" option like the "[" (and I wish I
> had
> found the drop option a year ago, and I wish that I had 1e6
> dollars... Oops,
> I mean euros).
>
>
> ## Make three example matricies
> exampGood = lapply(2:4, function(x)matrix(rnorm(1000*x),ncol=x))
> exampBad = lapply(1:3, function(x)matrix(rnorm(1000*x),ncol=x))
> ## Two ways to see what was created:
> for(k in 1:length(exampGood)) print(dim(exampGood[[k]]))
> for(k in 1:length(exampBad)) print(dim(exampBad[[k]]))
>
> ## Take the cumsum of each row of each matrix
> answerGood = lapply(exampGood, function(x) apply(x ,1,cumsum))
> answerBad = lapply(exampBad, function(x) apply(x ,1,cumsum))
>
> Try instead:
>
> answerBad = lapply(exampBad, function(x) as.matrix(apply(x ,
> 1:1,cumsum)))
>
>
> I also find wrapping as.matrix() around vector results inside a
> print() call often makes my console output much more to my liking.
>
>
> str(answerGood)
> str(answerBad)
>
> ## Take the first element of the final column of each answer
> for(mat in answerGood){
> LastColumn = ncol(mat)
> print(mat[1,LastColumn])
> }
> for(mat in answerBad){
> LastColumn = ncol(mat)
> print(mat[1,LastColumn])
> }
>
> [[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.
>
> David Winsemius, MD
> West Hartford, CT
>
>
David Winsemius, MD
West Hartford, CT
[[alternative HTML version deleted]]
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