* DEFINITION

* This is the header file for a library module used to calculate the median

* of a list of values. It finds the value that would be in the center if

* the list were sorted. If the list contains an even number of values, the

* lower of the two center values is reported. The values themselves are not

* sorted or modified in any way. This algorithm can be used as a filtering

* tool for rejecting noisy data.