buildin inv vs .qml.minv

Hi all,today i am calculating a lot of regression parameter, where theinverse of a triangular matrix is involved.(Normally the inverse is not needed, but this is another issue)I observe that sometimes/manytimes the builtin inv failed to returnthe inverse matrix. Does anybody has experience with this function?Regards,Kim

Any chance your matrix is singular?

On 22 Feb., 05:14, Aaron Davies <aaron.dav…> wrote:

> Any chance your matrix is singular?



Might be the case. But the point is that .qml.minv returns the inverse

where inv just returns 0h. I will try to generate/ or find an example

where inv fails to return a matrix.



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> On Monday, February 21, 2011, kuentang <kuent…> wrote:

>

> > Hi all,

>

> > today i am calculating a lot of regression parameter, where the

> > inverse of a triangular matrix is involved.

> > (Normally the inverse is not needed, but this is another issue)

>

> > I observe that sometimes/manytimes the builtin inv failed to return

> > the inverse matrix. Does anybody has experience with this function?

>

> > Regards,

> > Kim

>

> > –

> >

Submitted via Google Groups</kuent…></aaron.dav…>