Returns a simultaneous confidence band for the survival function.
Parameters:
alpha : float
1 - alpha is the desired simultaneous coverage
probability for the confidence region. Currently alpha
must be set to 0.05, giving 95% simultaneous intervals.
method : string
The method used to produce the simultaneous confidence
band. Only the Hall-Wellner (hw) method is currently
implemented.
transform : string
The used to produce the interval (note that the returned
interval is on the survival probability scale regardless
of which transform is used). Only log and arcsin are
implemented.
Returns:
lcb : array-like
The lower confidence limits corresponding to the points
in surv_times.
ucb : array-like
The upper confidence limits corresponding to the points
in surv_times.