Time for action – applying the ufunc methods on add

Let's call the four methods on add function.

1. The input array is reduced by applying the universal function recursively along a specified axis on consecutive elements. For the add function, the result of reducing is similar to calculating the sum of an array. Call the reduce method:

   a = np.arange(9)
   print "Reduce", np.add.reduce(a)

   The reduced array should be as follows:

   Reduce 36
   

2. The accumulate method also recursively goes through the input array. But, contrary to the reduce method, it stores the intermediate results in an array and returns that. The result, in the case of the add function, is equivalent to calling the cumsum function. Call the accumulate method on the add function:

   print "Accumulate", np.add.accumulate(a)

   The accumulated array:

   Accumulate [ 0  1  3  6 10 15 21 28 36]
   

3. The reduceat method is a bit complicated to explain, so let's call it and go through its algorithm, step-by-step. The reduceat method requires as arguments, an...