Numpy: calculate based on previous element?

Question

Say that I have array x and y:

x = numpy.array([1,2,3,4,5,6,7,8,9,10])  # actual content is the a result of another calculation step
         


        

Answer 1

Here is how you do it with Python:

x = [1, 2, 3, 4, 5, 6, 7, 8 ,9, 10]
y = [50]
for i in range(len(x)):
    y.append(y[-1] * 2 + x[i])
y = y[1:]

You might want to calculate it from the last element to prevent using the new values for the next i.