4 ms·
The value of Pi you mention was the one in the question, the one in the answer is: > For JPL's highest accuracy calculations, which are for interplanetary navi
by vanderZwan 4y ago
The value of Pi you mention was the one in the question, the one in the answer is:
> For JPL's highest accuracy calculations, which are for interplanetary navigation, we use 3.141592653589793. Let's look at this a little more closely to understand why we don't use more decimal places. I think we can even see that there are no physically realistic calculations scientists ever perform for which it is necessary to include nearly as many decimal points as you present.
That's sixteen digits, so a quick trip to the dev tools tels me::
>> Math.log2(3141592653589793)
-> 51.480417552782754
The last statement of the text I quoted is more interesting though. Although not surprising to me, given how many astronomers I know who joke that Pi equals three all the time.
- munro 4y agoLol I should RTFA ;D
- vanderZwan 4y agoNah, just claim you were invoking Cunningham's Law ;)
- Beltiras 4y agoI have horrid memories of debugging I had to do to get some god-awful fourier transform to calculate with 15 digits of precision to fit a spec. It's right at the boundary where double-precision stops being deterministic. Worst debugging week of my life.
- vanderZwan 4y ago> stops being deterministic I'm imagining the maths equivalent of Heisenbugs, is that correct?
- Beltiras 4y agoNo, just having to match how Matlab did the calculation (development of an index) to implementing the same thing in C++ (necessitating showing the calculation returned same significant digits for the precision we expected). I've seen a Heisenbug and that was really weird. Happened during uni so I didn't have to start tracing down compiler bugs. Not even sure if I could, happened with Java.