hi all I am porting some python code to java but got different results. after long time debugging, I found the reason is numpy's result is not the same as java(even the result of raw python codes) one case is: vector:[0.446141, 0.10414999999999996](that's not accurate) it's binary representation of IEEE754 is: 0.446141:0011111111011100100011011001001011111011000110011110011100110010 0.10419..:0011111110111010101010011001001100001011111000001101111011010000
dot product by java(or raw python) of x1*x1+x2*x2 is: 0.20988901438..(0011111111001010110111011010010010101010010001110010110101000011) but the result of pynum: x*x.T is: 0011111111001010110111011010010010101010010001110010110101000010 the last bit of mantissa is one difference. I don't floating points always hard to make sure to get same result in different environment(not only hardware but also software such as compiler optimizing and reordering) But I still want to know why, thanks. My environment: Python 2.7.3 (default, Sep 26 2013, 20:03:06) [GCC 4.6.3] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import numpy >>> numpy.version.version '1.6.1' _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
