## Creating your own functions

Posted February 27, 2013 at 02:49 PM | categories: python | tags: | View Comments

Updated March 06, 2013 at 06:29 PM

We can combine operations to evaluate complex equations. Consider the value of the equation \(x^3 - \log(x)\) for the value \(x=4.1\).

import numpy as np x = 3 print x**3 - np.log(x)

25.9013877113

It would be tedious to type this out each time. Next, we learn how to express this equation as a new function, which we can call with different values.

import numpy as np def f(x): return x**3 - np.log(x) print f(3) print f(5.1)

25.9013877113 131.02175946

It may not seem like we did much there, but this is the foundation for solving equations in the future. Before we get to solving equations, we have a few more details to consider. Next, we consider evaluating functions on arrays of values.

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