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qr.qy and qr.qty give an error message when y is integer and LAPACK=TRUE

3 messages · Berend Hasselman, Martin Maechler

Original
Berend Hasselman
# 
With this example

set.seed(123)
A <- matrix(runif(40), nrow = 8)
y <- 1:nrow(A)

A.laqr <- qr(A, LAPACK=TRUE)

both  qr.qy(A.laqr,y)  and  qr.qty(A.laqr,y)  give the respective error messages

Error in qr.qy(A.laqr, y) : 'b' must be a numeric matrix
Error in qr.qty(A.laqr, y) : 'b' must be a numeric matrix

However when Lapack is not used as in 

A.liqr <- qr(A, LAPACK=FALSE)

qr.qy(A.liqr,y) and qr.qty(A.liqr,y) don't issue error messages.

Looking at the source of qr.qy and qr.qty in https://svn.r-project.org/R/trunk/src/library/base/R/qr.R
I see that in the case of Lapack the storage.mode of y is not set to "double" (in contrast to when Linpack QR has been used).

I assume that the error issued when LAPACK=TRUE is not intended.

Berend

Suggested code change  in qr.qy
Replace 

    if(!is.null(a) && is.logical(a) && a)
        return(.Call("qr_qy_real", qr, as.matrix(y), 0, PACKAGE = "base"))

with

    if(!is.null(a) && is.logical(a) && a) {
        storage.mode(y) <- "double"
        return(.Call("qr_qy_real", qr, as.matrix(y), 0, PACKAGE = "base"))
    }

and a similar change in qr.qty
Martin Maechler
# 
> With this example

    > set.seed(123) A <- matrix(runif(40), nrow = 8) y <-
    > 1:nrow(A)

    > A.laqr <- qr(A, LAPACK=TRUE)

    > both qr.qy(A.laqr,y) and qr.qty(A.laqr,y) give the
    > respective error messages

    > Error in qr.qy(A.laqr, y) : 'b' must be a numeric matrix
    > Error in qr.qty(A.laqr, y) : 'b' must be a numeric matrix

    > However when Lapack is not used as in

    > A.liqr <- qr(A, LAPACK=FALSE)

    > qr.qy(A.liqr,y) and qr.qty(A.liqr,y) don't issue error
    > messages.

You are right... if you look at R 2.15.2 (or even it's patched
version).


    > Looking at the source of qr.qy and qr.qty in
    > https://svn.r-project.org/R/trunk/src/library/base/R/qr.R

Hmm, no: If  you really looked at that code (during the last several weeks),
you would have noted that the code has *changed* from what you
give below...

and the current R development version uses  
.Internal(.) instead of .Call()  and the C code behind the
.Internal() nicely deals with integer 'y' as well.

In short, this is already fixed in R, since ~ September,
but it won't probably be fixed in "R 2.15.2 patched" ...


Thank you for the report, anyway!
Martin



    > I see that in the case of Lapack the storage.mode of y is
    > not set to "double" (in contrast to when Linpack QR has
    > been used).



    > I assume that the error issued when LAPACK=TRUE is not
    > intended.

    > Berend

    > Suggested code change in qr.qy Replace

    >     if(!is.null(a) && is.logical(a) && a)
    > return(.Call("qr_qy_real", qr, as.matrix(y), 0, PACKAGE =
    > "base"))

    > with

    >     if(!is.null(a) && is.logical(a) && a) {
    > storage.mode(y) <- "double" return(.Call("qr_qy_real", qr,
    > as.matrix(y), 0, PACKAGE = "base")) }

    > and a similar change in qr.qty
    > ______________________________________________
    > R-devel at r-project.org mailing list
    > https://stat.ethz.ch/mailman/listinfo/r-devel
Berend Hasselman
#
On 03-12-2012, at 16:17, Martin Maechler wrote:

            

      
      
      
    

        
Which I did. And copied from R 2.15.2.

            

      
      
      
    

        
I did look at that code but did not drill down. Stupid.

            

      
      
      
    

        
Apologies for the noise.

Berend