Examples of: a) the true Φ(r) when P(R) is Gaussian; b) its corresponding diffusion signal E(q); c) a SW, Ψv,j (r). These wavelets aim to sparely represent signals of the type a), which seems quite reasonable; d) the response Ξ(q) to Ψv,j (r) in the space of measurements; e) a SR, which in [8] aims to sparsely represent signals of the type b). Note this shape prevents the use of SR to represent ODFs like a).