On Wed, 8 Sep 2010 15:44:02 -0400, Michael Gilbert wrote: > On Wed, Sep 8, 2010 at 12:23 PM, Charles R Harris wrote: > > > > > > On Wed, Sep 8, 2010 at 9:46 AM, Michael Gilbert > > <[email protected]> wrote: > >> > >> On Wed, 8 Sep 2010 09:43:56 -0600, Charles R Harris wrote: > >> > On Wed, Sep 8, 2010 at 9:26 AM, Michael Gilbert > >> > <[email protected] > >> > > wrote: > >> > > >> > > Hi, > >> > > > >> > > Are there any plans to add support for decimal floating point > >> > > arithmetic, as defined in the 2008 revision of the IEEE 754 standard > >> > > [0], in numpy? > >> > > > >> > > > >> > Not at the moment. There is currently no hardware or C support and > >> > adding > >> > new types to numpy isn't trivial. You can get some limited Decimal > >> > functionality by using python classes and object arrays, for instance > >> > the > >> > Decimal class in the python decimal module, but the performance isn't > >> > great. > >> > > >> > What is your particular interest in decimal support? > >> > >> Primarily avoiding catastrophic cancellation when subtracting > >> large values. I was planning to use the decimal class, but was > >> curious whether support for the IEEE standard was coming any time soon. > >> > > > > If you just need more precision, mpmath has better performance than the > > Decimal class. Also, it might be possible to avoid the loss of precision by > > changing the computation, but I don't know the details of what you are > > doing. > > Just wanted to say that numpy object arrays + decimal solved all of my > problems, which were all caused by the disconnect between decimal and > binary representation of floating point numbers. It would be really > nice to have IEEE decimal floating point since python's decimal module > is a bit slow, but I can see thats going to be a very long process.
FYI, gcc 4.2 introduced initial support for decimal floats. However, various macros like DEC32_MAX, and printf support for dd, df, and dl is not yet implemented making it rather hard to work with. Mike _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
