What does it mean for a signal to be sparse? Is that the same thing as sparse matrix in Matlab?

Are these the same thing? Does a sparse signal contain a lot of zeros with some portion being the relevant part?

Answer 1

[Wayne King]

Yes, that is essentially the definition. You should keep in mind that a signal may be sparse in some domain and not the other. For example, a sine wave is sparse in the Fourier domain, because a real-valued sine wave has only two nonzero coefficients in the Fourier domain.

Many signals are sparse in the wavelet domain.