On Tue, Jan 24, 2012 at 4:21 PM, Kathleen M Tacina < kathleen.m.tac...@nasa.gov> wrote:
> ** > I found something similar, with a very simple example. > > On 64-bit linux, python 2.7.2, numpy development version: > > In [22]: a = 4000*np.ones((1024,1024),dtype=np.float32) > > In [23]: a.mean() > Out[23]: 4034.16357421875 > > In [24]: np.version.full_version > Out[24]: '2.0.0.dev-55472ca' > > > But, a Windows XP machine running python 2.7.2 with numpy 1.6.1 gives: > >>>a = np.ones((1024,1024),dtype=np.float32) > >>>a.mean() > 4000.0 > >>>np.version.full_version > '1.6.1' > > > Yes, the results are platform/compiler dependent. The 32 bit platforms tend to use extended precision accumulators and the x87 instruction set. The 64 bit platforms tend to use sse2+. Different precisions, even though you might think they are the same. <snip> Chuck
_______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
