New timeseries object with samples occurring before event
ts1 = gettsbeforeevent(ts,event)
ts1 = gettsbeforeevent(ts,event,n)
ts1 = gettsbeforeevent(ts,event) returns a new timeseries object ts1 with samples occurring before an event in ts, where event can be either a tsdata.event object or a string. When event is a tsdata.event object, the time defined by event is used. When event is a string, the first tsdata.event object in the Events property of ts that matches the event name specifies the time.
When the timeseries object ts contains date strings and event uses numeric time, the time selected by the event is treated as a date that is calculated relative to the StartDate property in ts.TimeInfo.
When ts uses numeric time and event uses calendar dates, the time selected by the event is treated as a numeric value that is not associated with a calendar date.