works really well in the sense that if you train as possible to encoder like this weather color is linear and the encoder is a few layers of a neural net on the at least the columns of the decoding matrix end up being little parts of characters which means you can reconstruct any character with a linear combination of a small number of those things people call this call this these things atoms if you try our natural image patches this is a running algorithm running you end up with oriented edge detectors which is