Fast Inverse Square Root Function - Seems to have been created for Quake

[dangoldin]

http://www.scribd.com/vacuum?url=http://www.lomont.org/Math/Papers/2003/InvSqrt.pdf

[dangoldin]

The PDF: http://www.lomont.org/Math/Papers/2003/InvSqrt.pdf

[pchristensen → dangoldin]

It is at the point now where I click on the comments for every scribd.com story to see if someone has pasted in the original pdf url. Never fails.

[dangoldin → pchristensen]

I've noticed everyone likes the PDF version. It's trivial to add it as a comment since I have it copied in the clipboard from creating the submission - it's my standard practice now.

[axod → dangoldin]

Sure fire way to get karma it seems.

[dangoldin → axod]

Definitely. After a few hundred it doesn't really matter though.

[notauser → dangoldin]

Then why not submit the direct PDF link in the first place? Or is it a 'helpful' news.yc antifeature?

(PDF readers actually load faster than scribed, provided you aren't using the vanilla Adobe one with all the plugins turned on.)

[dangoldin → notauser]

It's a "helpful" feature. All PDF links are auto converted to scribd.

[xirium → dangoldin]

It would be more useful if the original hyperlink to a PDF file was preserved and a hyperlink to scribd was also presented. This would also eliminate a problem with duplicate hyperlink suppression.

[Kaizyn → notauser]

As most readers here already know, scribd is a YCombinator startup, so it's a useful feature for news.YC to have.

[apu]

The history of this function: http://www.beyond3d.com/content/articles/8/

Finding the original author of the function (Greg Walsh): http://www.beyond3d.com/content/articles/15/

[paulgb]

If you just want the big picture, this link is easier to skim:

http://betterexplained.com/articles/understanding-quakes-fas...

[mnemonicsloth]

No. The "inverse square root function" is the "square function."

What you want is a function that gives the inverse of a square root.

Mathematical terminology sucks.

[etal → mnemonicsloth]

I was thinking the same thing.

  int inverse_square_root(int x) { return x * x; } // patent pending

[zenspider]

great... now we can have all the posts that repeat every 3 months on programming.reddit repeat here too! YAY for signal:noise.

[huhtenberg → zenspider]

Just don't upvote the submission. If it's a major dupe, it will get off the front page very quickly.