Hi, On Sun, May 20, 2012 at 10:21 AM, Chao YUE <chaoyue...@gmail.com> wrote:
> Dear all, > > could anybody give one sentence about this? why in the loop I didn't get > zerodivision error by when I explicitly do this, I get a zerodivision > error? thanks. > > In [7]: for i in np.arange(-10,10): > print 1./i > ...: > -0.1 > -0.111111111111 > -0.125 > -0.142857142857 > -0.166666666667 > -0.2 > -0.25 > -0.333333333333 > -0.5 > -1.0 > inf > 1.0 > 0.5 > 0.333333333333 > 0.25 > 0.2 > 0.166666666667 > 0.142857142857 > 0.125 > 0.111111111111 > > In [8]: 1/0. > --------------------------------------------------------------------------- > ZeroDivisionError Traceback (most recent call last) > /mnt/f/data/DROUGTH/<ipython-input-8-7e0bf5b37da6> in <module>() > ----> 1 1/0. > > ZeroDivisionError: float division by zero > > In [9]: 1./0. > --------------------------------------------------------------------------- > ZeroDivisionError Traceback (most recent call last) > /mnt/f/data/DROUGTH/<ipython-input-9-3543596c47ff> in <module>() > ----> 1 1./0. > > ZeroDivisionError: float division by zero > > In [10]: 1./0 > --------------------------------------------------------------------------- > ZeroDivisionError Traceback (most recent call last) > /mnt/f/data/DROUGTH/<ipython-input-10-523760448f92> in <module>() > ----> 1 1./0 > > ZeroDivisionError: float division by zero You may like to read more on here http://docs.scipy.org/doc/numpy/reference/generated/numpy.seterr.html#numpy.seterr So, for your specific example: In []: a= arange(-10, 10) In []: 1./ a Out[]: array([-0.1 , -0.11111111, -0.125 , -0.14285714, -0.16666667, -0.2 , -0.25 , -0.33333333, -0.5 , -1. , inf, 1. , 0.5 , 0.33333333, 0.25 , 0.2 , 0.16666667, 0.14285714, 0.125 , 0.11111111]) In []: seterr(divide= 'raise') In []: 1./ a ------------------------------------------------------------ Traceback (most recent call last): File "<ipython console>", line 1, in <module> FloatingPointError: divide by zero encountered in divide My 2 cents, -eat > > > > Chao > > -- > > *********************************************************************************** > Chao YUE > Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL) > UMR 1572 CEA-CNRS-UVSQ > Batiment 712 - Pe 119 > 91191 GIF Sur YVETTE Cedex > Tel: (33) 01 69 08 29 02; Fax:01.69.08.77.16 > > ************************************************************************************ > > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > >
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