A numeric value, giving the aspect ratio for \(y\)-axis to \(x\)-axis \(y/x\) for the 2D case,
it is redundant in the 3D case (default is NA),
see the official help for asp by typing "? asp".
xlab, ylab, zlab
Titles for the \(x\) and \(y\) axes in the 2D case, and \(x\), \(y\), and \(z\) axes in the 3D case,
respectively (default is "" for all).