Algorithm 1.

Sequential optimization.

1. Set $k=0$, choose ${\mathbf{c}}_0$.

2. Repeat

3. ${\mathbf{c}}^{k+1}=\underset{\mathbf{c}}{\mathrm{argmin}}{\Vert p_m-\widehat{p}({\mathbf{c}}^k)\Vert }_2^2$

4. ${\mathbf{c}}^{k+1}={\mathbf{c}}^{k+1}/\mathrm{sum}({\mathbf{c}}^{k+1})$

5. ${\mathbf{c}}^{k+1}={({\mathbf{c}}^{k+1})}_{+}$

6. $k\leftarrow k+1$

7. Until stopping criterion is satisfied.