selectRois: Drawing the arrow indicating the current trace throws an error when trace plot is zoomed in.

[mjlm]

doAllClusterTraces draws an arrow using the annotation() function to indicate the current trace. This line throws an error when pressing "f" if the cluster trace plot is not zoomed out all the way. Probably due to the way the arrow location is calculated. Maybe just replace arrow by a text label, or a slightly thicker plot line or similar.