Writing your own functions

(60 minutes for all the sections below)

In an earlier section I talked about a “wall” of difficulty you can hit when working with RDataFrame. Here it is!

So far, I’ve done my best to assume that you’re familiar with no more than the basics of your programming language. From this point forward, in order to keep this tutorial to a reasonable length, I have to assume you know enough to write functions in your chosen language.

Python programmers: You’ve got it a bit harder, because you’re also going to have to learn something about C++ syntax.

I’ll provide examples from which you can extrapolate. But the burden of that extrapolation will rest on your shoulders.

I’ve broken this topic down into smaller chunks, to hopefully make it easier to absorb for those who don’t have prior experience with programming.

• Layers
• The C++ approach
• Lambda expressions in C++
• The Python approach
• Exercise 10: A more practical function

Figure 50: <https://xkcd.com/1270/> by Randall Munroe. Don’t worry, I’m not going to teach a functional programming language like LISP in this tutorial (though I admit I’m tempted).