# [R] Help on comparing two matrices

(Ted Harding) Ted.Harding at manchester.ac.uk
Sat Aug 22 23:24:52 CEST 2009

```Steve,
I don't know for sure whether this will help to solve your problem,
but you may be interested to read about the algorithm devised by
David Kendall for sorting 0-1 matrices, as described in

Incidence matrices, interval graphs and seriation in archeology.
Pacific J. Math. Volume 28, Number 3 (1969), 565-570

which is available on Open Access at Project Euclid:

http://projecteuclid.org/DPubS/Repository/1.0/Disseminate?
view=body&id=pdf_1&handle=euclid.pjm/1102983306

[also = http://tinyurl.com/mw2oap ]

On 22-Aug-09 19:38:47, Steve Lianoglou wrote:
> On Sat, Aug 22, 2009 at 2:45 PM, Michael Kogan <michael.kogan at gmx.net>
> wrote:
>
>>>
>>> 1. Sort the rows after the row sums (greater sums first).
>>> 2. Sort the columns after the first column (columns with ones in the
>>> first row go left, columns with zeros go right).
>>> 3. Save the left part (all columns with ones in the first row) and
>>> the right part in separate matrices.
>>> 4. Repeat steps 2 and 3 with both of the created matrices (now taking
>>> the second row for sorting), repeat until all fragments consist of a
>>> single column.
>>> 5. Compose the columns to a sorted matrix.
>
>> think you'd be best suited via some divide-and-conquer/recursion
>> route:
>
> Starting from step 2, that is.
>
> -steve
> --
> Steve Lianoglou
> Graduate Student: Computational Systems Biology
>| Memorial Sloan-Kettering Cancer Center
>| Weill Medical College of Cornell University
> Contact Info: http://cbio.mskcc.org/~lianos/contact
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.

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Date: 22-Aug-09                                       Time: 22:24:49
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