\figname{\zigfig} \midinsert \vbox{ \centerline{ \psfig{file=figures/zigfig.p,width=3in,bbllx=63pt,bblly=585pt,bburx=387pt,bbury=783pt} %\psfig{file=figures/zigfig.p,width=3in,bbllx=54pt,bblly=576pt,bburx=396pt,bbury=7%74pt} } \medskip \figurecaption{\zigfig}{Backfitting to the least squares linear fit with two covariates. The residual $\vec r^{(m)}$ converges to the least-squares residual $\vec y^{\perp}$ in a zigzag fashion. In the figure, all vectors are projected onto the $({\vec x}_1,{\vec x}_2)$-plane.}* } % end vbox \endinsert