[Rd] eigen returns NAs from a real matrix

Duncan Murdoch murdoch at stats.uwo.ca
Mon Mar 19 14:33:26 CET 2007


On 3/19/2007 9:12 AM, Martin Maechler wrote:
>>>>>> "Duncan" == Duncan Murdoch <murdoch at stats.uwo.ca>
>>>>>>     on Mon, 19 Mar 2007 09:01:39 -0400 writes:
> 
>     Duncan> On 3/19/2007 6:48 AM, Martin Maechler wrote:
>     >>>>>>> "BDR" == Prof Brian Ripley <ripley at stats.ox.ac.uk>
>     >>>>>>> on Sun, 18 Mar 2007 06:51:58 +0000 (GMT) writes:
>     >> 
>     BDR> On Sat, 17 Mar 2007, Spencer Graves wrote:
>     >> >> Hi, All:
>     >> >> Attached please find a symmetric, indefinite matrix for which 
>     >> >> 'eigen(...)$vectors' included NAs: 
>     >> >>> load("eigenBug.Rdata")
>     >> >>> sum(is.na(eigen(eigenBug)$vectors))
>     >> >> [1] 5670
>     >> >>> sessioninfo()
>     >> >> Error: could not find function "sessioninfo"
>     >> >>> sessionInfo()
>     >> >> R version 2.4.1 (2006-12-18)
>     >> >> i386-pc-mingw32
>     >> >> 
>     >> >> locale:
>     >> >> LC_COLLATE=English_United States.1252;LC_CTYPE=English_United 
>     >> >> States.1252;LC_MONETARY=English_United 
>     >> >> States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252
>     >> >> 
>     >> >> attached base packages:
>     >> >> [1] "stats"     "graphics"  "grDevices" "utils"     "datasets"  "methods" [7] 
>     >> >> "base"
>     >> >> Using EISPACK does NOT return NAs: > sum(is.na(eigen(eigenBug, 
>     >> >> EISPACK=TRUE)$vectors))
>     >> >> [1] 0
>     >> >> 
>     >> >> 
>     >> >> I traced the problem to the following line in 'eigen':
>     >> >> z <- if (!complex.x)
>     >> >> .Call("La_rs", x, only.values, PACKAGE = "base")
>     >> >> 
>     >> >> 
>     >> >> Comments?
>     >> 
>     BDR> Nothing appeared as an attachment.
>     >> 
>     >> it was a zip file which is not among the allowed ones
>     >> (.tar.gz / *.tgz  would work).
>     >> 
>     >> Spencer has also contacted me in private,
>     >> so you now can use something like :
>     >> 
>     >> F <- tempfile()
>     >> download.file("ftp://stat.ethz.ch/U/maechler/R/eigenBug.Rdata", F)
>     >> load(F)
> 
>     Duncan> This is unrelated to Spencer's problem, but this
>     Duncan> sequence failed for me.
> 
>     Duncan> By default it will treat the file as a text file,
>     Duncan> and convert EOL markers for Windows.  Adding
>     Duncan> "mode='wb'" to the download.file() call is necessary.
> 
> ok;  Thank you, Duncan.
> 
> {For me, that's yet another reason why I think it would be  ``nice''
>  if both  load() and source()  would work with general
>  connections the same way as read.table(), and I could just say
> 
>      load("ftp://stat.ethz.ch/U/maechler/R/eigenBug.Rdata")
> }
> 
>     >> str(eigenBug)# tons of dinames; get rid of them:
>     >> M <- unname(eigenBug)
>     >> 
>     >> sum(is.na(eigen(M)$vectors))
>     >> # 0 (for MM, on Linux);  '5670' for Spencer
> 
>     Duncan> I get the same as Spencer in 2.4.1, but zero in
>     Duncan> R-devel, in Windows. 
> 
> ahh, that's good news.
> 
> Maybe Spencer could install a revcent version R-devel on his
> Windows machine, and try the example?
> 
> 
>     Duncan> I haven't tried R-patched yet: there were network
>     Duncan> problems here this morning, and the build failed.

I just tried it, and it gives the error the same as R 2.4.1.

Duncan Murdoch

> 
>     Duncan> Duncan Murdoch
> 
>     >> sum(is.na(eigen(M, EISPACK=TRUE)$vectors))
>     >> # 0
>     >> 
>     >> ## Guess about what kind of BLAS/Lapack I'm using :
>     >> file.info(list.files(R.home("lib"), full=TRUE))[,1:3]
>     >> ##                                        size isdir mode
>     >> ## ....64-linux-inst/lib/libRblas.so    422558 FALSE  755
>     >> ## ....64-linux-inst/lib/libRlapack.so 3144596 FALSE  755
>     >> 
>     >> 
>     >> I.e. I don't get any NA's
>     >> which shows to me that the bug is most probably in the Lapack -
>     >> Version that Spencer's version of R is linked against.
>     >> 
>     >> Martin Maechler, ETH Zurich
> 
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