It's not, though... In sparse coding, you're generally using an over-complete set of vectors which decompose the data into sparse activations. So, if you have

It's not, though... In sparse coding, you're generally using an over-complete set of vectors which decompose the data into sparse activations. So, if you have a dataset of hundred dimensional vectors, you want to find a set of vectors where each vector is well described as a combination of ~4 of the "basis" vectors.