On 9/9/11 1:54 PM, Gilles Sadowski wrote:
> On Fri, Sep 09, 2011 at 11:26:02AM -0700, Phil Steitz wrote:
>> On 9/9/11 9:27 AM, Ted Dunning wrote:
>>> I don't think that is correct.
>>>
>>> It is not the case that there was some element in the input that was too
>>> small. For instance, this matrix
On Fri, Sep 9, 2011 at 1:54 PM, Gilles Sadowski <
gil...@harfang.homelinux.org> wrote:
> > > The exceptions thrown should not be sub-classes of
> NumberIsTooSmallException
> > > because it is a matrix that is the problem and matrices are not numbers
> and
> > > do not have a total order.
>
> Of co
On Fri, Sep 09, 2011 at 11:26:02AM -0700, Phil Steitz wrote:
> On 9/9/11 9:27 AM, Ted Dunning wrote:
> > I don't think that is correct.
> >
> > It is not the case that there was some element in the input that was too
> > small. For instance, this matrix is positive definite:
> >
> > 3 -3
On 9/9/11 9:27 AM, Ted Dunning wrote:
> I don't think that is correct.
>
> It is not the case that there was some element in the input that was too
> small. For instance, this matrix is positive definite:
>
> 3 -31
> 242
> 11 30
>
> While this one is not
>
> 3
I don't think that is correct.
It is not the case that there was some element in the input that was too
small. For instance, this matrix is positive definite:
3 -31
242
11 30
While this one is not
3 -31
232
11 30
The value of the
Actually, I think that the test in the Cholesky decomposition should be
three-pronged:
lt[i] > threshold proceed normally, use sqrt(lt[i])
lt[i] >= -threshold treat as zero. Either return rank-deficient result
if pivoting or
signal that original argument is not
Looks good to me.
On Fri, Sep 9, 2011 at 6:39 AM, Gilles Sadowski <
gil...@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. Th
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 a
On Thu, Sep 08, 2011 at 09:27:18PM -0500, Greg Sterijevski wrote:
> I agree with Ted. You sometimes run into this issue with psuedoinverses. You
> discover a zero eigenvalue at index i. The user's natural inclination is to
> attribute it to the corresponding column of the data matrix.
>
> -Greg
>
I agree with Ted. You sometimes run into this issue with psuedoinverses. You
discover a zero eigenvalue at index i. The user's natural inclination is to
attribute it to the corresponding column of the data matrix.
-Greg
On Thu, Sep 8, 2011 at 6:55 PM, Ted Dunning wrote:
> OK.
>
> Replace that w
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 val
On Thu, Sep 08, 2011 at 09:36:47AM -0700, Ted Dunning wrote:
> Since the diagonal elements are heavily modified during the Cholesky
> decomposition, it isn't clear what these actually mean.
>
> With pivoting, the meaning of these is even less clear.
>
> Also, I thought that the test for non-posit
Since the diagonal elements are heavily modified during the Cholesky
decomposition, it isn't clear what these actually mean.
With pivoting, the meaning of these is even less clear.
Also, I thought that the test for non-positive definiteness was whether the
diagonal element after reduction from pr
Hi.
In revision 1166674, I've added an argument to that exception so that it can
print the value that failed the test.
However, I also wonder whether the message should not be
---CUT---
not positive definite matrix: diagonal element at ({1},{1}) is not strictly
larger than {2} ({0})"
---CUT---
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