When you have a variable that could contain a numeric range of data and you want to “map” it to a new range. (For instance I have a variable that has a range of numbers from -1 to 1, yet I want to “map” it to a range of numbers from 0 to 400). We can use the map function:
// if oldValue goes from -1 to 1
// newValue will go from 0 to 400
// For instance if oldValue=0.5, newValue=300
let newValue=map(oldValue,-1,1,0,400);
The basic trigonometry functions are extremely useful for generative art. I like to use these functions for two reasons, the first is that no matter what “x” value I pass to sin(x) or cos(x), I know it will always return a number from -1 to 1. Second, I like to use these functions, especially with movement because I know that their results will look more natural than movement that happens linearly over time.
https://en.wikipedia.org/wiki/Sine_and_cosine
From Class, creating an interesting design using Sin. Feel free to change some of the parameters to see how it effects the design:
Another example (similar, not covered in class):
Look at the source at P5 Editor
Notice how the balls moving in the following sketch appear to move with a rhythm that looks more natural:
Bouncing Ball with Sin at P5 Editor