ELI5: Explain Like I'm 5

Wirtinger derivatives

Okay kiddo, let me explain something to you called Wirtinger derivatives. Do you know what a derivative is?

It's like when you want to know how fast something is changing. You can think of it like a car going down a road - the car's speedometer tells you how fast it's going, but the car can speed up, slow down, or turn, and you want to know how all of those changes affect its speed. That's what a derivative helps with - it tells you how much things are changing at any given moment.

Now, a Wirtinger derivative is a special kind of derivative that's used in math. It's named after a guy named Wilhelm Wirtinger who came up with it a long time ago.

The simplest way to think of a Wirtinger derivative is that it's like a regular derivative, but it's used for functions that have something called a "complex variable". A complex variable is a fancy way of saying that there are two things that are changing at once, kind of like a two-for-one deal.

So, if you try to take a regular derivative of a complex variable function, it can get a bit tricky because there are two things changing at once. That's where the Wirtinger derivative comes in - it can handle those kinds of functions and tell you how they're changing.

For example, let's say you have a function that describes a wave in the ocean. That function has a complex variable because the wave can be moving up and down (like a rollercoaster) and side to side (like a boat swaying). The Wirtinger derivative can tell you how fast the wave is moving in both directions at the same time!

I hope that helps, kiddo. Math can be tricky sometimes but it's always exciting to learn new things!