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# numpy.select

`numpy.``select`(condlist, choicelist, default=0)

  Return an array drawn from elements in choicelist, depending on conditions.

  Parameters: | condlist : list of N boolean arrays of length M The conditions C_0 through C_(N-1) which determine from which vector the output elements are taken. choicelist : list of N arrays of length M Th vectors V_0 through V_(N-1), from which the output elements are chosen.
  Returns: | output : 1-dimensional array of length M The output at position m is the m-th element of the first vector V_n for which C_n[m] is non-zero. Note that the output depends on the order of conditions, since the first satisfied condition is used.

  Notes

  Equivalent to:

      output = []
      for m in range(M):
          output += [V[m] for V,C in zip(values,cond) if C[m]]
                    or [default]

  Examples

      >>> t = np.arange(10)
      >>> s = np.arange(10)*100
      >>> condlist = [t == 4, t > 5]
      >>> choicelist = [s, t]
      >>> np.select(condlist, choicelist)
      array([  0,   0,   0,   0, 400,   0,   6,   7,   8,   9])

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