Finds the median value of a series.
Optional. A series, defaults to the current Window.
returns 4, because there are two observations greater than four and two lower.
returns 6.0, the average of the two middle values.
MEDIAN must SORT the input series, which can be time consuming for large data.
See COLMEDIAN to find the median of each column of a table.
See MOVMEDIAN to compute the moving median of a series.
See BLOCKMEDIAN to compute the non-overlapping block median of a series.