Sequential Analysis

isMonotonicIncreasing	Check whether the elements in X are monotonically increasing.
isMonotonic	Alias for isMonotonicIncreasing.
isMonotonicDecreasing	Check whether the elements in X are monotonically decreasing.
isPeak	If X is a vector, check if each element in X is the peak.
isValley	If X is a vector, check if each element in X is the valley.
zigzag	zigzag is mainly used to filter values with smaller movements in HL.