Terrence Brannon wrote:
> John Randall <[EMAIL PROTECTED]> writes:
>
>>
>> I think we are being thrown by a possible misprint.
>> Perhaps Terrence can supply a context.
>>
>
> Well, the Pike code is here for compose:
> http://shootout.alioth.debian.org/gp4/benchmark.php?test=pidigits&lang=pike&id=0
>
> All of the programs are viewable here:
> http://shootout.alioth.debian.org/gp4/benchmark.php?test=pidigits&lang=all
>
> as well as a pointer to the paper that the code was derived from.
>

>From page 7 of the paper:

"Such a transformation can be represented by the four coefficients
q,r,s,t, and if they are arrange as a matrix

q r
s t

then function composition corresponds to matrix multiplication.

....

comp (q,r,s,t) (u,v,w,x) = (q*u+r*w,q*v+r*x,s*u+t*w,s*v+t*x)

"

I don't know what the Pike code is doing, but it looks like one should be
multiplying 2x2 matrices, as I suggested.

Best wishes,

John

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