search for: indicator_r

Recently, I ran a series of Kruskal-Wallace tests [kruskal.test()] using by() to group by site Output is a list: >Herb.KW Herb.df$ID: 10-1 Kruskal-Wallis rank sum test data: Indicator_Rating by Year Kruskal-Wallis chi-squared = 15.24, df = 7, p-value = 0.03302 ----------------------------------------------------------------------------------------------------- Herb.df$ID: 18-1 Kruskal-Wallis rank sum test data: Indicator_Rating by Year Kruskal-Wallis chi-squared = 13...

...wever, my data has multiple sites on which KW needs to be run... here's the data: Herb.df<- data.frame(Score=rep(c(2,4,6,6,6,5,7,8,6,9),2),Year=rep(c(rep(1,5),rep(2,5)),2),Site=c(rep(3,10),rep(4,10))) However, if I try this: tapply(Herb.df,Herb.df$Site,function(.data) kruskal.test(.data$Indicator_Rating,.data$Year)) >Error in tapply(Herb.df, Herb.df$ID, function(.data) kruskal.test(.data$Indicator_Rating, : arguments must have same length How can I vectorize the kruskal.test() for all sites using tapply() in lieu of a loop? -- View this message in context: http://n4.nabble.com...