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From Greg Sterijevski <gsterijev...@gmail.com>
Subject Re: [Math] "NonPositiveDefiniteMatrixException" message and meaning
Date Fri, 09 Sep 2011 12:52:58 GMT
Looks good to me.

On Fri, Sep 9, 2011 at 6:39 AM, Gilles Sadowski <
gilles@harfang.homelinux.org> wrote:

> On Thu, Sep 08, 2011 at 04:55:46PM -0700, Ted Dunning wrote:
> > OK.
> >
> > Replace that with the correct value.  I meant it to be an index.
> >
> > That doesn't change my other points.  There is an inherent problem with
> > "less than" comments when you have subtracted several other elements
> > previously and only now notices that the remainder is less than some
> other
> > adjusted value.  The user cannot relate either value back to anything
> that
> > they have and they may well look at their own matrix and see the opposite
> > condition.  It is better to give a slightly more abstract message such as
> > "Non-positive definiteness in input detected at diagonal element number
> xxx"
>
> What do you think of the following message?
>
> <element value> is smaller than, or equal to, the minimum (<threshold
> value>):
> not positive definite matrix: value <element value> at index <element
> index>
>
> where, in actual messages, the <...> will be the numeric values of course.
>
> "NonPositiveDefiniteMatrixException" would inherit from
> "NumberIsTooSmallException". The rationale being that it exactly matches
> the
> test and that it is meaningless to report an element of the original
> matrix,
> as you've explained.
>
> > [...]
>
> Gilles
>
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