On 02/27/2012 08:02 AM, Grant Edwards wrote: > On 2012-02-27, Steven D'Aprano <steve+comp.lang.pyt...@pearwood.info> wrote: >> On Sun, 26 Feb 2012 16:24:14 -0800, John Ladasky wrote: >> >>> Curiosity prompts me to ask... >>> >>> Those of you who program in other languages regularly: if you visit >>> comp.lang.java, for example, do people ask this question about >>> floating-point arithmetic in that forum? Or in comp.lang.perl? >> >> Yes. >> >> http://stackoverflow.com/questions/588004/is-javascripts-math-broken >> >> And look at the "Linked" sidebar. Obviously StackOverflow users no >> more search the internet for the solutions to their problems than do >> comp.lang.python posters. >> >> http://compgroups.net/comp.lang.java.programmer/Floating-point-roundoff-error > > One might wonder if the frequency of such questions decreases as the > programming language becomes "lower level" (e.g. C or assembly).
I think that most of the use cases in C or assembly of math are integer-based only. For example, counting, bit-twiddling, addressing character cells or pixel coordinates, etc. Maybe when programmers have to statically declare a variable type in advance, since the common use cases require only integer, that gets used far more, so experiences with float happen less often. Some of this could have to do with the fact that historically floating point required a special library to do floating point math, and since a lot of people didn't have floating-point coprocessors back then, most code was integer-only. Early BASIC interpreters defaulted to floating point for everything, and implemented all the floating point arithmetic internally with integer arithmetic, without the help of the x87 processor, but no doubt they did round the results when printing to the screen. They also did not have very much precision to begin with. Anyone remember Microsoft's proprietary floating point binary system and how there were function calls to convert back and forth between the IEEE standard? Another key thing is that most C programmers don't normally just print out floating point numbers without a %.2f kind of notation that properly rounds a number. Now, of course, every processor has a floating-point unit, and the C compilers can generate code that uses it just as easily as integer code. No matter what language, or what floating point scheme you use, significant digits is definitely important to understand! -- http://mail.python.org/mailman/listinfo/python-list
