Outliers

Create vectors of outliers and non-outliers according to either Grubbs or Interquartile range method

Given a column vector X of data points, this function creates two vectors, one with non-outliers, Y, and one with outliers, out.
The user can choose one of two different methods, either Grubbs' test statistic or the interquartile range method.
The user can also choose the degree of strictness when removing outliers. In both methods, the degree of strictness is negatively related to the parameter alpha (i.e. the higher alpha, the fewer the outliers that are identified and removed).