bt.margin: Margins of the plot as used by
par("mar"). The default is c(0.5, 1, 0, 0).
bt.color_surface: Color of the surface of the
perspective plot. The default is "lightgrey".
bt.color_branches: Color used for the branches of the
barrier tree. Per default there will be one color per level.
bt.persp_border: Color of the lines / borders around
each facet of the perspective plot. The default is "grey".
bt.persp_shade: A ratio defining the shade of the
surface. The default is 0.35.
bt.persp_{theta, phi}: Angles (in degree) defining the
viewing direction of the perspective plot. theta corresponds to
the azimuthal direction (default: 330) and phi to the
colatitude (default: 15).
bt.persp_{xlab, ylab, zlab}: Labels of the x-, y- and z-
axis. The defaults are expression(x[1]),
expression(x[2]) and expression(f(x[1], x[2]))
bt.persp_ticktype: Should the values of each dimension
be shown in detail ("detailed") or just via "simple"
arrows in direction of increasement along the axes? The default is
"detailed".
bt.col_root: Color of the root symbol. The default is
"red".
bt.pch_root: Symbol used for plotting the root.
The default is 17 (filled triangle).
bt.pch_breakpoint: Symbol used for plotting a
breakpoint. The default is 5 (non-filled diamond).
bt.pch_basin: Symbol used for plotting the leaf (i.e. a
basin) of the barrier tree. The default is 19 (filled circle).
bt.lwd: Width of the lines used for plotting the
branches of a barrier tree. The default is 2.