Fabrice Silva wrote: > Le vendredi 14 octobre 2011 à 08:04 -0400, Neal Becker a écrit : >> suppose I have: >> >> In [10]: u >> Out[10]: >> array([[0, 1, 2, 3, 4], >> [5, 6, 7, 8, 9]]) >> >> And I have a vector v: >> v = np.array ((0,1,0,1,0)) >> >> I want to form an output vector which selects items from u where v is the >> index of the row of u to be selected. >> >> In the above example, I want: >> >> w = [0,6,2,8,4] >> >> I can't seem to find a syntax that does this. >> >> Now, more importantly, I need the result to be a reference to the original >> array >> (not a copy), because I'm going to use it on the LHS of an assignment. Is >> this possible? > > What about np.where? > http://docs.scipy.org/doc/numpy/reference/generated/numpy.where.html > > w = np.where(v, u[1], u[0]) > > if you may want to have more than two options (more than two lines for > u), then np.choose may be more appropriate > http://docs.scipy.org/doc/numpy/reference/generated/numpy.choose.html
Will np.choose result in a lval? _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
