Hi, Am I right in thinking that float96 on windows 32 bit is a float64 padded to 96 bits? If so, is it useful? Has anyone got a windows64 box to check float128 ?
Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import numpy as np >>> np.__version__ '1.6.1' >>> info = np.finfo(np.float96) >>> print info Machine parameters for float96 --------------------------------------------------------------------- precision= 15 resolution= 1e-15 machep= -52 eps= 2.22044604925e-16 negep = -53 epsneg= 1.11022302463e-16 minexp=-16382 tiny= 0.0 maxexp= 16384 max= 1.#INF nexp = 15 min= -max --------------------------------------------------------------------- >>> info.nmant 52 Confirming 52 (+1 implicit) significand digits >>> np.float96(2**52)+1 4503599627370497.0 >>> np.float96(2**53)+1 9007199254740992.0 float96 claims 15 exponent digits (nexp above), but in fact it appears to have 11, as does float64 >>> np.float64(2**1022) * 2 8.9884656743115795e+307 >>> np.float64(2**1022) * 4 __main__:1: RuntimeWarning: overflow encountered in double_scalars inf >>> np.float96(2**1022) * 2 8.9884656743115795e+307 >>> np.float96(2**1022) * 4 1.#INF It does take up 12 bytes (96 bits) >>> np.dtype(np.float96).itemsize 12 Thanks, Matthew _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
