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From: | Marco Caliari |
Subject: | Re: the competition's expm vs ours |
Date: | Wed, 10 Dec 2008 09:23:48 +0100 (CET) |
On 9-Dec-2008, Jaroslav Hajek wrote: I wonder whether there's room to optimize further, but I don't see anything left.
If you allow to precompute another auxiliary matrix a4 = a2^2; then you can rewrite x = (c(8) * a4 + c(6) * a2) * a4 + c(4) * a4 + c(2) * a2 + id;At this point, you can even increase by one the degree of the approximation (at the same cost) and write
y = ((c(9) * a4 + c(7) * a2) * a4 + c(5) * a4 + c(3) * a2 + c(1) * id) * aa;
Of course, you need a new set of coefficients c(1:9). Best regards, Marco
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