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0 pointsCogitoCogito6y ago0 comments

> I don't know that it is "wrong", just unexpected. I suspect most people expect all math functions to be purely implemented in numerical terms, so finding string manipulation is surprising/interesting.

You kind of got me thinking now. The decimal representation of a number is really a string representation (in the sense of a certain sequence of characters). Hence rounding to a certain decimal is essentially a string operation. You can of course do it by (say) dividing by 10^whatever or something else in some numerical fashion, but the more I think about it, the more natural it is to just think of the whole thing as a string.

Or you could flip it around and consider that the string manipulation can also be described numerically so whether you consider the operation as a string operation or a numerical operation is sort irrelevant. It's just a point of view.

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Frost1x6y ago

I think the best way to think about it is as a symbolic representation. We have processes for manipulating symbols to achieve the correct results. Purely numeric (binary based) operations just happen to allow for some quicker shortcuts but sometimes lead go lost information.

kthejoker26y ago

This is one of the core ground/figure themes in Godel Escher Bach.

xamuel6y ago

>The decimal representation of a number is really a string representation

It is incorrect to speak of "the" decimal representation of a number, as many numbers have non-unique decimal representations, the most famous example being 1.000...=0.999...

bloomer6y ago

The definition that makes it unique is the shortest representation where trailing zeros are bout included. In your example that would be 1 note that this definition comes up in binary floating point where there are infinite decimal representations that will round back to a given binary64 float but the decimal representation chosen is the shortest (and closest to the binary64 float in the case of ties for length).

CogitoCogitoOP6y ago

> It is incorrect to speak of "the" decimal representation of a number, as many numbers have non-unique decimal representations, the most famous example being 1.000...=0.999...

That's true and I'll concede that point, but it's not really relevant to what I said. That just means some numbers have different string representations that represent the same object. That doesn't really contradict anything in my post except the use of the definite article.

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