On 14-Jul-09, at 3:33 PM, Greg Fiske wrote: > Dear list, > > > > I'm learning to work with numpy arrays. Can somebody explain how to > get the > average of two separate arrays while ignoring a user defined value > in one > array? > > > > For example: > >>>> a = numpy.array([1,5,4,99]) > >>>> b = numpy.array([3,7,2,8]) > > > > Ignoring the value 99, the result should be an array like c= > ([2,6,3,8])
The simplest way I can think of doing it: In [60]: c = concatenate((a[newaxis,:], b[newaxis,:]),axis=0) In [61]: c = where(c == 99, nan, float64(c)) In [62]: nansum(c,axis=0) / (~isnan(c)).sum(axis=0) Out[62]: array([ 2., 6., 3., 8.]) The last line could be replaced with scipy.stats.nanmean(c, axis=0) if you have scipy installed. David _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
