Re: [Numpy-discussion] Number of digits

[David D. <dav...@lo...>]

On Mon, Jul 10, 2006 at 08:46:33AM -0500, Robert Kern wrote:
> Tim Hochberg wrote:
> > Nils Wagner wrote:
> >> Hi all,
> >>
> >> how can I increase the number of digits in the output of str(.) ?
> >>  =20
> > You can't as far as I know. For floats, you can use "%.nf". For example:
> >=20
> > "%.13f" % 493.4802200544680
>=20
> The problem is is that he doesn't have a float. He has one of our float64=
scalar=20
> objects. The str() of a real Python float will give as many digits as are=
=20
> necessary to recreate number and no more (or maybe one or two more). A st=
r() of=20
> a float64scalar will round according to some rule that I haven't figured =
out,=20
> yet. It doesn't seem to be configurable with numpy.set_printoptions().

This is a different ptoblem from the one exposed by Nils. I mean, tha
fact that str() on numpy.float64 objects is somewhat obscure is a
problem that should obviously be addressed some day. However, as far as
I understand Nils' message, the "%.13f" trick is enough for what he
need. But I may be wrong... He just want to "increase the number of
digits", not have the "optimal" number of digits (as long as this is
meaningfull).

But I may have missed something.

David

--=20
David Douard                             LOGILAB, Paris (France)
Formations Python, Zope, Plone, Debian : http://www.logilab.fr/formations
D=E9veloppement logiciel sur mesure :      http://www.logilab.fr/services
Informatique scientifique :              http://www.logilab.fr/science