ELI5: Explain Like I'm 5

Eigendecomposition of a matrix

Have you ever played with building blocks before? A matrix is like a special set of building blocks that you use to do math. When you have a matrix, you might want to know some special things about it, like how it moves things around or how it stretches or shrinks them.

One way to figure these things out is by breaking the matrix into smaller pieces. This is where eigendecomposition comes in. It's like taking a big tower of blocks and breaking it into smaller towers that are easier to understand.

To do this, we use a special kind of block called an "eigenvector". An eigenvector is like a magic block that, when you put it through the matrix, it only gets stretched or shrunk. It doesn't get turned or rotated or anything like that.

Once we find all the eigenvectors, we use them to build new blocks called "eigenvalues". An eigenvalue is like a little instruction that tells us how much each eigenvector stretches or shrinks.

Finally, we put all these pieces together to make a new matrix that has just the eigenvectors and eigenvalues. This new matrix is much easier to understand because we can see exactly how it stretches, shrinks, and moves things around.

So there you have it, eigendecomposition in a nutshell. It's like breaking down a big tower of blocks into smaller, easier-to-understand towers using magic blocks called eigenvectors and instructions called eigenvalues.