Add fitted line to a plot. This is overloaded function for robust regression methods from package depthproc.

# S4 method for RobReg
abline(
a = NULL,
b = NULL,
h = NULL,
v = NULL,
reg = NULL,
coef = NULL,
untf = FALSE,
...
)

## Arguments

a an object of class RobReg not used. not supported. not supported. not supported. not supported. not supported. Arguments to be passed to methods, such as graphical parameters (see par).