> I would also suggest to go that way since we can then merge the ticket
> dependent on it. Once we have the correctly, but not blazingly fast
> version in Sage we can always switch to the C++ version as it is
> convenient for the integrators.
+1 -- all those lovely doctests will not go to waste
On Feb 25, 11:07 am, [EMAIL PROTECTED] wrote:
> On Mon, 25 Feb 2008, Carlo Hamalainen wrote:
> > On Mon, Feb 25, 2008 at 6:20 AM, <[EMAIL PROTECTED]> wrote:
> >> Dirty, William. I can't believe you blame this on me -- that was all
> >> Robert's fault. Anyway. I've co-opted Ajanki's framewo
On Mon, 25 Feb 2008, Carlo Hamalainen wrote:
> On Mon, Feb 25, 2008 at 6:20 AM, <[EMAIL PROTECTED]> wrote:
>> Dirty, William. I can't believe you blame this on me -- that was all
>> Robert's fault. Anyway. I've co-opted Ajanki's framework, and have
>> rewritten the core of the search algor
On Sat, 23 Feb 2008, William Stein wrote:
>
> On Sat, Feb 23, 2008 at 12:46 PM, <[EMAIL PROTECTED]> wrote:
>>
>>
>>
>>
>> On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
>>
>> >
>> > On Fri, Feb 22, 2008 at 8:55 PM, <[EMAIL PROTECTED]> wrote:
>> >> Arguments for including Ajanki's code:
>> >>
On Sat, Feb 23, 2008 at 12:46 PM, <[EMAIL PROTECTED]> wrote:
>
>
>
>
> On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
>
> >
> > On Fri, Feb 22, 2008 at 8:55 PM, <[EMAIL PROTECTED]> wrote:
> >> Arguments for including Ajanki's code:
> >> 1) It's the only Python implementation of DLX I've
On Sat, 23 Feb 2008, Carlo Hamalainen wrote:
>
> On Fri, Feb 22, 2008 at 8:55 PM, <[EMAIL PROTECTED]> wrote:
>> Arguments for including Ajanki's code:
>> 1) It's the only Python implementation of DLX I've seen.
>> 2) I emailed the author, who happily added the "or later" bit after th
On Fri, Feb 22, 2008 at 8:55 PM, <[EMAIL PROTECTED]> wrote:
> Arguments for including Ajanki's code:
> 1) It's the only Python implementation of DLX I've seen.
> 2) I emailed the author, who happily added the "or later" bit after the
> GPL2
> 3) With my Sage Matrix -> DLXMatrix code
matics
* Fordham University
* Bronx, NY, USA
*
* Office: John Mulcahey Hall, Room 421
* Phone: +1-718-817-3222
* Fax: +1-240-363-0240 (an e-fax)
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To "sage-devel@googlegroups.com"
, "Gregory Bard" <[EMAIL PROTECTED]>
If it is an NP-complete problem, presumably it asks whether such a set
of rows exists, not that you find one.
Bill.
On 22 Feb, 21:32, Robert Miller <[EMAIL PROTECTED]> wrote:
> Just a technical note: Mod 2 matrices are not the natural way to think
> about adjacency matrices (I learned this the h
Just a technical note: Mod 2 matrices are not the natural way to think
about adjacency matrices (I learned this the hard way) - the entry is
actually better thought of as the number of paths of length one from
one vertex to another. That way taking nth powers of the matrices
counts the number of n
In this context I think that binary means all the entries are 1s and zeros.
But when you look for a set of rows that add up to [1,1,1,...], you don't
consider 1+1=0. This makes sense when you want only one 1 to appear in each
column, which is a natural requirement, and makes the problem much harde
The original problem said "binary matrix" so surely that means mod 2?
And I would expect mod 2 matrices to come up in the graph theory
applications. Not that I know about that...
John
On 22/02/2008, William Stein <[EMAIL PROTECTED]> wrote:
>
> On Fri, Feb 22, 2008 at 12:50 PM, David Harvey
>
On Fri, Feb 22, 2008 at 12:50 PM, David Harvey
<[EMAIL PROTECTED]> wrote:
>
>
> On Feb 22, 2008, at 3:49 PM, William Stein wrote:
>
> >
> > On Fri, Feb 22, 2008 at 12:04 PM, Jason Grout
> > <[EMAIL PROTECTED]> wrote:
> >>
> >> [EMAIL PROTECTED] wrote:
> >>> I've found a nice implementation
On Feb 22, 2008, at 3:49 PM, William Stein wrote:
>
> On Fri, Feb 22, 2008 at 12:04 PM, Jason Grout
> <[EMAIL PROTECTED]> wrote:
>>
>> [EMAIL PROTECTED] wrote:
>>> I've found a nice implementation of the DLX algorithm, which
>>> "quickly" solves the NP-Complete exact cover problem. For those
On Fri, Feb 22, 2008 at 12:04 PM, Jason Grout
<[EMAIL PROTECTED]> wrote:
>
> [EMAIL PROTECTED] wrote:
> > I've found a nice implementation of the DLX algorithm, which "quickly"
> solves the NP-Complete exact cover problem. For those who aren't in Seattle
> and haven't heard me blathering on a
[EMAIL PROTECTED] wrote:
> I've found a nice implementation of the DLX algorithm, which "quickly" solves
> the NP-Complete exact cover problem. For those who aren't in Seattle and
> haven't heard me blathering on and on and on and on about how awesome DLX
> is...
>
> Let M be a binary matrix.
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