Delete these two lines, since we can estimate a sparseMM with intercept, when the 1-columns is not added.
In the computation of a weighted lasso, change the mean to be computed as a weighted mean (not as a mean of the weighted observations), center before transforming variables
As a result the weighted mean of the residuals is now 0.
(If we don't have this, sparse S and S do not give the same results for lambda very small.)