Comparing the algorithms in Figures 1 and 2, we notice three differences between BLasso and Boosting: (i) the use of backward steps in BLasso; (ii) BLasso uses the grid search (fixed step size) for feature selection in Equation 12while Boosting uses the continuous search (optimal step size) in Equation 7; and (iii) BLasso uses a fixed step size for feature update in Equation 13while Boosting uses an optimal step size in Equation (8).
f-Boosting was implemented as figure 2, by setting a large value to θ in Equation (15), i.e., θ = 10 3 , to prohibit backward steps.