Fig 4.

Phase diagrams corresponding to the change-point model. Left: CASE; the boundary is decided by $(4-10\vartheta )+2\sqrt{{(2-5\vartheta )}^2-{\vartheta }^2}$ (left part) and 4(1 − ϑ) (right part). Right: hard thresholding; the upper boundary is decided by $2{(1+\sqrt{1-\vartheta })}^2$ and the lower boundary is decided by 2ϑ.