A color palette, that is a vector of n contiguous colors generated by functions like rainbow, heat.colors, topo.colors, bpy.colors or one or your own making, perhaps using colorRampPalette. If none is provided, rev(terrain.colors(255)) is used unless x has a 'color table'
breaks
numeric. A set of finite numeric breakpoints for the colours: must have one more breakpoint than colour and be in increasing order
alpha
If TRUE a fourth layer to set the background transparency is added
colNA
color for the background (NA values)
zlim
vector of lenght 2. Range of values to plot
zlimcol
If NULL the values outside the range of zlim get the color of the extremes of the range. If zlimcol has any other value, the values outside the zlim range get the color of NA values (see colNA)
ext
An Extent object to zoom in to a region of interest (see drawExtent)