On Oct 2, 10:12?pm, "Gabriel Genellina" <[EMAIL PROTECTED]> wrote: > En Tue, 02 Oct 2007 01:59:35 -0300, [EMAIL PROTECTED] > <[EMAIL PROTECTED]> escribi : > > > How does gmpy make the conversion from float to rational? > > Well, you know, these days valuable software usually comes with something > people call "documentation". Incomprehensible documents in strange formats > talking about esoteric stuff that nobody is able to read (as if someone > wanted to actually read them!). > Hidden in the land of Mordor where the shadows lie, there is an ancient > scroll -a long time forgotten by mankind- where you can read terrible > things like this: > > "If an mpf or float argument is passed, the > mpq is built from it with an 'optimal' approach based on a > Stern-Brocot tree." <http://gmpy.googlecode.com/svn/trunk/doc/gmpydoc.txt> > > On the motivation for doing such evil things, you can read the explanation > given centuries ago by its creator, by then the High Wizard Alessandro: > > "[The algorithm tries] to convert floats to rationals > giving the smallest denominator compatible with the hypothesis that > the float is precise to N bits [...] usually DBL_MANT_BITS [...] normally > 53 today" > > <http://mail.python.org/pipermail/python-list/2002-October/166974.html> >
The best place to hide something is in the documentation. Which I have read often, but that's one of the places where my eyes glaze over. Thanks anyway. And to Robert Kern also. > -- > Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list