Keflavich wrote: > [snip] > > I feel fairly certain, however, that floats are exactly what I want > for my purposes: I need moderately high precision and I'm not > concerned about the least-significant-bit errors except when they > violate function domains. I guess the overriding lesson is that every > float subtraction needs to be carefully thought through, which is a > disappointing loss of simplicity for me, but I'll deal with it. > > Adam
floats probably are what you want, but in some corner cases you have to do further math in order for your computer not to blow up; an option may be to use Taylor expansions at some point before your function call, if you can see a case of problematic arguments creeping up like that. And in general you have to use something like "abs(x-y) < epsilon" in place of x==y, as you said. If it is simple enough, could you post the piece of code that leads to the x you use in arcsin(x)? There's a chance that someone may figure a place where a numerical trick could be used in your code. -- http://mail.python.org/mailman/listinfo/python-list
