Table 2. Table of notations.
| Notation | Description |
|---|---|
| x | Original signal |
| M | Number of measurements |
| y | Compressed sample |
| ϕ | CS matrix |
| Ψ | Transform matrix |
| K | Signal sparsity level |
| g | Sparse presentation of x |
| r | Residual of y |
| X | Wolf position |
| Xp | Prey position |
| q | Number of selected columns by Wolf algorithm |
| Xα | α Wolf position |
| Xβ | β Wolf position |
| Xδ | δ Wolf position |
| R | Support set |
| C | Search set |
| φc | Sub-matrix contains columns with indices c from φ matrix |
| best | Best solution or Xα |
| Secbest | Second best solution or Xβ |
| thirbest | Third best solution or Xδ |
| f | Fitness value |
| x′ | Estimated solution |
| t | Number of iterations |
| † | Pseudo-inverse |
| L | Indices set of largest K magnitude entries in |