I grew up a TI guy - my recollection is that they stated in the user manual that though the display could show "only" 10 decimal digits, memory saved and computations used 16; perhaps nowadays it is even more, but unless you're doing millions of sequential calculations (how often do you do that on a handheld scientific calculator?) you shouldn't be seeing cumulative error problems, right?
DG Christopher Barker wrote: > Robert Kern wrote: > >> Christopher Barker wrote: >> >>> I wonder if there are any C math libs that do a better job than you'd >>> expect from standard FP? (short of unlimited precision ones) >>> >> With respect to π and the zeros of sin() and cos()? Not really. If >> numpy.sin(numpy.pi) were to give you 0.0, it would be *wrong*. numpy.sin() is >> supposed to give you the most accurate result representable in >> double-precision >> for the input you gave it. >> > > But does it? > > >> numpy.pi is not π. >> > > More precisely, it's the best IEEE754 64 bit FP approximation of pi. > > Right. I think that was the trick that HP used -- they somehow stored > and worked with pi with more digits. The things you can do if you're > making dedicated hardware. > > I do wonder if there would be some way to use the extended precision > built in to Intel FP hardware -- i.e. have a pi that you can pass in > that has the full 80 bits that can be used internally. I don't know if > the trig functions can be done with extended precision though. > > -Chris > > > _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
