[Octave-bug-tracker] [bug #29432] Sin(1e22) is wrong

[Judd Storrs]

Follow-up Comment #8, bug #29432 (project octave):

I think the originator choose 1e22 based on knowledge of floating point
representation and possibly with knowledge of trig-function algorithm
implementations--other than that I don't know why getting large sin()s correct
would matter? Frankly, in terms of correctness, any number between -1 and +1
is plausible as the result of sin(1e22) with ieee doubles since:


octave:1> format long
octave:2> x = (1e22)-(2*pi) ;
octave:3> y = (1e22)+(2*pi) ;
octave:4> x-y
ans = 0


I just assume this is a special diagnostic feature. Or I guess it could be an
algorithmic fingerprint. I just thought I'd send in the test in the chance it
was useful. It's not so that's fine.

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