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Numpy Beginner's Guide (Update)
book

Numpy Beginner's Guide (Update)

by Ivan Idris
June 2015
Beginner
348 pages
8h 44m
English
Packt Publishing
Content preview from Numpy Beginner's Guide (Update)

Time for action – calculating the Exponential Moving Average

Given an array, the exp() function calculates the exponential of each array element. For example, look at the following code:

x = np.arange(5)
print("Exp", np.exp(x))

It gives the following output:

Exp [  1.           2.71828183   7.3890561   20.08553692  54.59815003]

The linspace() function takes as parameters a start value, a stop value, and optionally an array size. It returns an array of evenly spaced numbers. This is an example:

print("Linspace", np.linspace(-1, 0, 5))

This will give us the following output:

Linspace [-1.   -0.75 -0.5  -0.25  0.  ]

Calculate the EMA for our data:

  1. Now, back to the weights, calculate them with exp() and linspace():
    N = 5
    weights = np.exp(np.linspace(-1., 0., N))
  2. Normalize the ...
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Publisher Resources

ISBN: 9781785281969