From: jhr.walter@t-online.de (Joerg Walter)
Subject: Performance problem with bg
Date: Thu, 11 Dec 2003 20:19:31 +0100
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Dear Prof. Davis,

I'm studying Steven Morgan's thesis on 'A Comparison of Simplex Method
Algorithms' and am porting the codes to C++. I love Steven's work and feel
obliged to report a performance problem.

Steven uses the following form in bg.m to compute the modified cost vector:

c_tilde(:,V_indices) = c(:,V_indices) - c(:,B_indices) * (U \ (L \
A(:,V_indices)));

I believe

c_tilde(:,V_indices) = c(:,V_indices) - ((c(:,B_indices) / U) / L) *
A(:,V_indices);

is way more efficient (and I see this in my C++ codes, at least ;-)

Thanks,
Joerg Walter