On Jan 4, 10:00 am, "siggi" <[EMAIL PROTECTED]> wrote: > Thanks for that, too! > > Would be interesting to learn how these different algorithms [for pow] > influence the > precision of the result!?
For an integer (i.e., int or long) x and a nonnegative integer y, x**y is exact: >>> 1000001 ** 12 1000012000066000220000495000792000924000792000495000220000066000012000001L (73 significant digits, correctly ending in "000001") math.pow uses floating-point arithmetic (even if you pass it integers), and so has limited precision: >>> print '%.73f' % math.pow(1000001, 12) 1000012000066000238472777842004463257260700063242258506335663988477526016 (Only the first 17 digits are correct.) For floats, the ** operator does the same thing math.pow does. -- http://mail.python.org/mailman/listinfo/python-list
