Sunday, November 3, 2013

Lesson 34 - Wheel of fortune

Am I running out of descriptive titles for posts?

Today we continued on our professional audio API project.

The goal is to create functions for playing the familiar "taa" and "ti" notes (quarter-note, eight-note) with different pitches. This requires us to write functions with parameters, which isn't actually entirely new to us. So, we want a function that can be used to play an eight-note of any pitch. For example to play C:

    ti c

The "c" here actually refers to the frequency of the C note (261.63 Hz) and is a parameter of the function "ti".

We wrote the "ti" function like

    let ti n = play n 100

This translates to "to play an eight note of frequency n, you should plan the n note for 100 milliseconds". I explained the idea of a function parameter to her so that when you call the function, the parameter n will be replaced by the note you give to the function. And used a couple of examples.

Then we tried the function like

    ti e

And it worked like a charm. Then she wrote the similar function "taa" mosly by herself. It worked too. I'm glad she used a different arbitrary name for the function parameter, to illustrate that the computer doesn't really care about the names; they are merely for us humans to care about.

Then she saved the file.

    save "nakki"

Arbitrary names seems to be the way to go. We'll continue our program next time.

Why Wheel of Fortune? It's just the movement she makes with her hand while looking up the letters on the keyboard. Circling around the keyboard like an eagle looking for prey. Not that she misses often.


  1. you should *plan > play

    *mosly > mostly

    Good stuff! Wonder why this kind of projects aren't more common in the internets...

  2. Whoa. I recognize the wheel of fortune/eagle movement on my 3-year old daughter, who's still just learning the letters. She knows already maybe about 8 letters but it's sometimes very hard to find some of them in the keyboard.

    How old was your coder-daughter when she learned all the letters?

  3. She knew most letters before turning 4. Some letters (DFGB) are still tough though. The coding lessons have taught her to master even those letters quite well.