Helper function for graphing ellipses from eigendecompositions. This function is used by bvNormalContour and confidenceEllipse. Essentially this is a wrapper for draw.ellipse that also calculates appropriate x-axis and y-axis limits to make graphing an ellipse easier (because the entire ellipse should be visible without any work on the user's part to specify the limits).
eigenEllipseHelper(mu, lengths, angle, xl, yl, lim.adj, axes, center, ...)column matrix giving the coordinates for the cener of the ellipse.
vector giving the major and minor axis lengths.
angle of rotation (in radians).
x-axis limits. If xl = NULL then these are computed automatically.
y-axis limits. If yl = NULL then these are computed automatically.
a value giving an adjustment to the x-axis and y-axis limits computed if either xl = NULL or yl = NULL.
logical. If axes = TRUE, then the major and minor axes are graphed.
logical. If axes = TRUE then the center of the ellipse is indicated with a point and dashed lines are drawn to the x-axis and y-axis.
other arguments to be passed to the graphing functions.
None