Table II. OS-SQS Methods.

1: Initialize x(0) and compute D.

2: for n = 0, 1, …

3: for m = 0, 1, …, M − 1

4: k = nM + m

5: ${\mathit{x}}^{\left(\frac{k+1}{M}\right)}=\mathcal{P}\chi [{\mathit{x}}^{\left(\frac{k}{M}\right)}-{\mathit{D}}^{-1}M\nabla {\mathrm{\Psi }}_m({\mathit{x}}^{(\frac{k}{M})})]$