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 -- Fabrice Silva