% -*- texinfo -*- % @deftypefn {Function File} {[@var{pval}, @var{z}] =} wilcoxon_test (@var{x}, @var{y}, @var{alt}) % For two matched-pair sample vectors @var{x} and @var{y}, perform a % Wilcoxon signed-rank test of the null hypothesis PROB (@var{x} > % @var{y}) == 1/2. Under the null, the test statistic @var{z} % approximately follows a standard normal distribution when @var{n} > 25. % % @strong{Warning}: This function assumes a normal distribution for @var{z} % and thus is invalid for @var{n} <= 25. % % With the optional argument string @var{alt}, the alternative of % interest can be selected. If @var{alt} is @code{'~='} or % @code{'<>'}, the null is tested against the two-sided alternative % PROB (@var{x} > @var{y}) ~= 1/2. If alt is @code{'>'}, the one-sided % alternative PROB (@var{x} > @var{y}) > 1/2 is considered. Similarly % for @code{'<'}, the one-sided alternative PROB (@var{x} > @var{y}) < % 1/2 is considered. The default is the two-sided case. % % The p-value of the test is returned in @var{pval}. % % If no output argument is given, the p-value of the test is displayed. % @end deftypefn

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