

   PPlloott RRiiddggee FFuunnccttiioonnss ffoorr PPrroojjeeccttiioonn PPuurrssuuiitt RReeggrreessssiioonn FFiitt

        plot.ppr(fit, ask, type="o", ...)

   AArrgguummeennttss::

        fit: A fit of class `"ppr"' as produced by a call to
             `ppr'.

        ask: the graphics parameter `ask': see `par' for
             details. If set to `True' will ask between the
             plot of each cross-section.

       type: the type of line to draw

        ...: further graphical parameters

   VVaalluuee::

        None

   SSiiddee EEffffeeccttss::

        A series of plots are drawn on the current graphical
        device, one for each term in the fit.

   SSeeee AAllssoo::

        `ppr', `par'

   EExxaammpplleess::

        data(rock)
        attach(rock)
        area1 <- area/10000; peri1 <- peri/10000
        par(mfrow=c(3,2))# maybe: , pty="s")
        rock.ppr <- ppr(log(perm) ~ area1 + peri1 + shape,
                  data=rock, nterms=2, max.terms=5)
        plot(rock.ppr, main="ppr(log(perm)~ ., nterms=2, max.terms=5)")
        plot(update(rock.ppr, bass=5), main = "update(..., bass = 5)")
        plot(update(rock.ppr, sm.method="gcv", gcvpen=2),
             main = "update(..., sm.method=

