ranksum (Statistics Toolbox)

ranksum. Wilcoxon rank sum test that two populations are identical ... p = ranksum(x,y,alpha) returns the significance probability that the populations ... StatisticsToolbox     ranksum Wilcoxonranksumtestthattwopopulationsareidentical Syntax p=ranksum(x,y,alpha) [p,h]=ranksum(x,y,alpha) [p,h,stats]=ranksum(x,y,alpha) Description p=ranksum(x,y,alpha) returnsthesignificanceprobabilitythatthepopulationsgeneratingtwoindependentsamples,xandy,areidentical.xandyarebothvectors,butcanhavedifferentlengths.alphaisthedesiredlevelofsignificanceandmustbeascalarbetweenzeroandone. [p,h]=ranksum(x,y,alpha) alsoreturnstheresultofthehypothesistest,h.hiszeroifthepopulationsofxandyarenotsignificantlydifferent.hisoneifthetwopopulationsaresignificantlydifferent. pistheprobabilityofobservingaresultequallyormoreextremethantheoneusingthedata(xandy)ifthenullhypothesisistrue.Ifpisnearzero,thiscastsdoubtonthishypothesis. [p,h,stats]=ranksum(x,y,alpha) alsoreturnsastructurecontainingthefieldstats.ranksumwhosevalueisequaltotheranksumstatistic.Forlargesamples,italsocontainsstats.zvalthatisthevalueofthenormal(Z)statisticusedtocomputep. Example Thisexampleteststhehypothesisofequalityofmeansfortwosamplesgeneratedwithpoissrnd. x=poissrnd(5,10,1); y=poissrnd(2,20,1); [p,h]=ranksum(x,y,0.05) p= 0.0027 h= 1 SeeAlso signrank,signtest,ttest2   range raylcdf