Infinite-precision arithmetic

[xbury.cs at clearstream.com]

If you want to tackle multiplications, you should do it via bases...
10 and 2 being the easiest but not the most efficient.

Knowing the laws of power series and logs will be of great help
as they can tell you what digit goes where... But Rev can't handle
the sums so you need an array (or items) to do the digit/symbol
segmentation per polinomial level.

So in the end, it's like doing the math with paper and pencil ;)

cheers
Xav

On 24.05.2005 11:55:25 use-revolution-bounces wrote:
>sez xbury.cs at clearstream.com:
>>Very nice!
>Thanks!
>
>>That's the easy part though ;)
>[nods] Don't I know it!
>
>>Divisions is where it gets harder...
>And square roots... and powers... and DIV and MOD... and...
>I've already come up with an infinite-precision algorithm for
>multiplication which looks promising; I haven't coded it up yet, however, 
so I 
>am not
>entirely certain how well it will work out "in real life". In pseudocode:
>
>InfPreMult N1, N2
>put 0 into Rezult
>Put N1 into Fred
>Repeat until N2 = 0
>If N1 is odd then add Adder to Rezult
>Add Fred to Fred
>put N1 div 2 into N1
>end repeat
>End of algorithm
>
>Naturally, there's also the option of splitting N1 and N2 up into
>7-character chunks, doing all the multiplies for the relevant 
chunk-pairs, and
>combining the results of said multiplies. That looks like it'd be a pain 
to 
>code, so
>I am going to try the other algorithm first. Depending on how fast it is, 
I
>may or may not want to give "7-char chunks" a try as well.
>
>>...and using arrays may be much more efficient than using strings or
>numbers...
>>But items could work well too but wouldn't it be slower?
>I've never touched arrays before. I shall have to see if arrays make a
>difference, speed-wise. Every millisecond -- heck, every *micro*second -- 
counts
>in this sort of thing.
>_______________________________________________
>use-revolution mailing list
>use-revolution at lists.runrev.com
>http://lists.runrev.com/mailman/listinfo/use-revolution


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