On Tue, May 22, 2012 at 6:33 AM, Chao YUE <[email protected]> wrote:
> Just in case some one didn't know this. Assign a float number to an integer > array element will always return integer. right -- numpy arrays are typed -- that's one of the points of them -- you wouldn't want the entire array up-cast with a single assignment -- particularly since there are only python literals for a subset of the numpy types. > so I would always do this if I expected a transfer from integer to float? > In [18]: b=a.astype(float) yes -- but that's an odd way of thinking about -- what you want to do is think about what type you need your array to be before you create it, then create it the way you need it: In [87]: np.arange(5, dtype=np.float) Out[87]: array([ 0., 1., 2., 3., 4.]) or better: In [91]: np.linspace(0,5,6) Out[91]: array([ 0., 1., 2., 3., 4., 5.]) note that most (all?) numpy array constructors take a "dtype" argument. -Chris > In [19]: b > Out[19]: array([ 2., 4., 6., 8., 10.]) > > In [20]: b[1]=4.5 > > In [21]: b > Out[21]: array([ 2. , 4.5, 6. , 8. , 10. ]) > > thanks et cheers, > > 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 > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion > -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception [email protected] _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
