2008/5/8 Charles R Harris <[EMAIL PROTECTED]>: > > David, what you are using is a log(log(x)) representation internally. IEEE > is *not* linear, it is logarithmic.
As Robert Kern says, yes, this is exactly what the OP and all the rest of us want. But it's a strange thing to say that IEEE is logarithmic - "2.3*10**1" is not exactly logarithmic, since the "2.3" is not the logarithm of anything. IEEE floats work the same way, which is important, since it means they can exactly represent integers of moderate size. For example, 257 is represented as sign 0, exponent 135, (implied leading 1).00000001b. The exponent is indeed the integer part of the log base 2 of the value, up to some fiddling, but the mantissa is not a logarithm of any kind. Anyway, all this is immaterial. The point is, in spite of the fact that floating-point numbers can represent a very wide range of numbers, there are some important contexts in which this range is not wide enough. One could in principle store an additional power of two in an accompanying integer, but this would be less efficient in terms of space and time, and more cumbersome, when for the usual situations where this is applied, simply taking the logarithm works fine. Anne _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion