levelplot.panel.levelplot(x, y, z, 
                subscripts,
                at = pretty(z),
                shrink,
                labels = NULL,
                label.style = c("mixed", "flat", "align"),
                contour = FALSE,
                region = TRUE,
                col = add.line$col,
                lty = add.line$lty,
                lwd = add.line$lwd,
                cex = add.text$cex,
                font = add.text$font,
                fontfamily = add.text$fontfamily,
                fontface = add.text$fontface,
                col.text = add.text$col,
                ...,
                col.regions = regions$col,
                alpha.regions = regions$alpha)
panel.contourplot(...)x,y,z to drawregion=TRUE.  Usually a subset of
    the colors are used, the exact number being one more than the length
    of at.  These are chosen to be roughly equally spaced along
    col.regions.  levelplot and
  contourplot (which differ only in default values of some
  arguments). panel.contourplot is a simple wrapper to
  panel.levelplot.  When contour=TRUE, the contourLines function is used to
  calculate the contour lines.
levelplot, contourLines