Re: [Rd] non user-friendly error for chol2inv functions

From: christophe dutang <dutangc_at_gmail.com>
Date: Fri, 29 Aug 2008 14:28:42 +0200

Yes, I do not cast the first argument as a matrix with as.matrix function. Maybe we could detail the error message if the first argument is a numeric?

error(_("'a' is a numeric and must be coerced to a numeric matrix"));

Thanks for your answer

2008/8/29 Martin Maechler <maechler_at_stat.math.ethz.ch>

> >>>>> "cd" == christophe dutang <dutangc@gmail.com>
> >>>>> on Fri, 29 Aug 2008 12:44:18 +0200 writes:
>
> cd> Hi,
> cd> In function chol2inv with the option LINPACK set to false (default),
> it
> cd> raises an error when the matrix is 1x1 matrix (i.e. just a real)
> saying
>
> cd> 'a' must be a numeric matrix
>
> It is very helpful, but you have to read and understand it.
> I'm pretty sure you did not provide a 1 x 1 matrix.
>
> Here's an example showing how things works :
>
> > m <- matrix(4,1,1)
> > cm <- chol(m)
> > cm
> [,1]
> [1,] 2
> > chol2inv(cm)
> [,1]
> [1,] 0.25
> >
>
> Martin Maechler, ETH Zurich
>
>
> cd> This error is raised by the underlying C function (modLa_chol2inv in
> cd> function Lapack.c). Everything is normal, but I wonder if we could
> have
> cd> another behavior when we pass a 1x1 matrix. I spent time this
> morning
> cd> finding where was the error, and it was this "problem".
>
> cd> Thanks in advance
>
> cd> Christophe
>
> cd> [[alternative HTML version deleted]]
>
> cd> ______________________________________________
> cd> R-devel_at_r-project.org mailing list
> cd> https://stat.ethz.ch/mailman/listinfo/r-devel
>

        [[alternative HTML version deleted]]



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