How to find the most common range of values in a Matrix

I have a very large matrix and I am trying to find most common range at the top end of the values of the matrix to then determine extraneous points. Any help hugely appreciated thanks in advance

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/fileexchange/28501-tests-to-identify-outliers-in-data-series