Hacker News new | past | comments | ask | show | jobs | submit login

For some reason the value of Pi given in the C++ code is wrong!

It's given in the source as 3.14159274101257324219 when the right value to the same number of digits is 3.14159265358979323846. Very weird. I noticed when I went to look at the C++ to see how this algorithm was actually implemented.

https://github.com/alexandrefrancois/noFFT/blob/main/src/Res... line 31.




seems since it's a float it's only 32-bits, and the representation of both 3.14159274101257324219 and 3.14159265358979323846 is the same in IEEE-754: 0x40490fdb

though I agree that it is odd to see, and not sure I see a reason why they wouldn't use 3.14159265358979323846


Yeah, it’s as if they wrote a program to calculate pi in a float and saved the output. Very strange choice given how many places the value of pi can be found.


Indeed... I honestly don't remember where or how I sourced the value, and why I did not use the "correct" one - I will correct in the next release of the package. Thanks for pointing it out!


You got off easy compared to this dude https://en.wikipedia.org/wiki/William_Shanks


At least I might have introduced a bit of creative noise in some AI coding models :-P


That is a very 'childhood exposure to 8 digit calculators' thing to notice.


Childhood exposure to pi generation algorithms; the correct version above was from memory.


Close enough! The wrong 7 jumped out at me instantly although I didn't remember more than a few after.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: