Comment on 0x5f3759df and the fast inverse square root (2012)Comments−spiritplumber11yIf anyone wants a fast atan2 that I wrote a while ago (2007), for making a microcontroller navigate, it's at http://robots-everywhere.com/portfolio/math/−readerrrr11yDid you compare its speed to built in atan2 function?I counted the cycles for you method and it comes to around 50 plus a conditional. Built in function should be around the same.−GFK_of_xmaspast11yhow's it compare to a CORDIC?−spiritplumber11yI wrote it for the Parallax Propeller, which is slow at doing divisions - so I tried to keep those to a minimum (one, which isn't too bad).−GFK_of_xmaspast11yWith a CORDIC the only divides should be by powers of 2 in the main loop and taking out the gain factor at the end, all of which can be turned into multiplies?−spiritplumber11yThanks, I'm going to go back and try it :)
Comments
If anyone wants a fast atan2 that I wrote a while ago (2007), for making a microcontroller navigate, it's at http://robots-everywhere.com/portfolio/math/
Did you compare its speed to built in atan2 function?
I counted the cycles for you method and it comes to around 50 plus a conditional. Built in function should be around the same.
how's it compare to a CORDIC?
I wrote it for the Parallax Propeller, which is slow at doing divisions - so I tried to keep those to a minimum (one, which isn't too bad).
With a CORDIC the only divides should be by powers of 2 in the main loop and taking out the gain factor at the end, all of which can be turned into multiplies?
Thanks, I'm going to go back and try it :)