% Test for outlying or inlying variance % % Description: % % This test is useful to check if largest variance in several groups % of data is 'outlying' and this group should be rejected. % Alternatively, if one group has very small variance, we can test % for 'inlying' variance. % % Usage: % % [pval,C] = cochrantest(x,inlying,n) % % Arguments: % % x: A vector of variances or matrix of observations. % % n: If object is a vector, n should be another vector, giving % number of data in each corresponding group. If object is a % matrix, n should be omitted. % % inlying: Test smallest variance instead of largest. % % Details: % % The corresponding p-value is calculated using 'cochrancdf' function. % % Value: % % C: the value of Cochran-statistic. % % p.value: the p-value for the test. % % % Author(s): % % Lukasz Komsta, ported from R package 'outliers'. % See R News, 6(2):10-13, May 2006 % % References: % % Snedecor, G.W., Cochran, W.G. (1980). Statistical Methods (seventh % edition). Iowa State University Press, Ames, Iowa. % % %