>>>>> David Reiner <david.rei...@xrtrading.com>
>>>>> on Wed, 15 Aug 2012 09:59:10 -0500 writes:
> As a mathematician, I have to correct the subject line
> to 'Distributive Matrix operations' -- David
Yes, indeed;
that was *really* disturbing to me as well, about this thread!
{in addition to the fact that he should have used all.equal()
and not identical() as someone had pointed out already ..}
And at last: Yes, some of the methods for Diagonal() matrices in the
'Matrix' package did have bugs, in earlier versions.
NOTE: You can (and often should) update packages also if for
some reason you cannot update your version of R!
Martin Maechler, ETH Zurich
> -----Original Message----- From:
> r-help-boun...@r-project.org
> [mailto:r-help-boun...@r-project.org] On Behalf Of
> Doran, Harold Sent: Tuesday, August 14, 2012 12:55 PM
> To: Berend Hasselman Cc: 'r-help@r-project.org' Subject:
> Re: [R] Communative Matrix Multiplcation
> Thanks, Berend. I updated my R and got same result. I
> reposted the old sessionInfo(), which was an older
> version. But, same code, same matrices, different result
>> -----Original Message----- From: Berend Hasselman
>> [mailto:b...@xs4all.nl] Sent: Tuesday, August 14, 2012
>> 1:49 PM To: Doran, Harold Cc: 'r-help@r-project.org'
>> Subject: Re: [R] Communative Matrix Multiplcation
>>
>>
>> On 14-08-2012, at 19:26, Doran, Harold wrote:
>>
>> >
>> > I'm not seeing why the following occurs:
>> >
>> > T1 <- (A1 - A2) %*% D
>> > T2 <- (A1 %*% D) - (A2 %*% D)
>> > identical(T1, T2)
>> [1] FALSE
>>
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