Hello everybody, I was wondering if there is an elegant way of overwriting 'nan' string representation with 'NaN' when saving numpy array containing np.nan values with numpy.savetxt() function. numpy.set_printoptions(nanstr='NaN') setting (which has default value of 'NaN' already) does not seem to have any effect when writing array to the file, only when printing to the screen: $ python Python 2.5.2 (r252:60911, Sep 30 2008, 15:42:03) [GCC 4.3.2 20080917 (Red Hat 4.3.2-4)] on linux2 Type "help", "copyright", "credits" or "license" for more information.

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import numpy as np print np.__version__ 1.3.0 np.get_printoptions() {'infstr': 'Inf', 'threshold': 1000, 'suppress': False, 'linewidth': 75, 'edgeitems': 3, 'precision': 8, 'nanstr': 'NaN'}

a = np.array([1, 2, 3, np.nan]) a array([ 1., 2., 3., NaN]) np.savetxt('testa.txt', a)

$ cat testa.txt 1.000000000000000000e+00 2.000000000000000000e+00 3.000000000000000000e+00 nan $ Many thanks, Masha