Solved – Error within the dependent variable while running a RM ANOVA using ezANOVA

I'm having a problem running a repeated-measures ANOVA in R using the ezANOVA function.

I have data from 20 subjects – each subject participated in 2 conditions and 2 laps (80 total data points in a balanced design with no missing cells).

When I try to run the full RM ANOVA

model<-ezANOVA(data=RMdata            ,dv=sd_speed            ,wid=P            ,within=c("Pr","lap")            ,type=3) 

I get the following error over and over again:

Error in ezANOVA_main(data = data, dv = dv, wid = wid, within = within,  :    "dv" must be numeric. 

But the dv (sd_speed) is numeric!

Classes ‘grouped_df’, ‘tbl_df’, ‘tbl’ and 'data.frame': 80 obs. of  4 variables:  $ P       : Factor w/ 20 levels "1","2","3","4",..: 1 2 3 4 5 6 7 8 9 10 ...      $ Pr      : Factor w/ 2 levels "control","VPA": 1 1 1 1 1 1 1 1 1 1 ...  $ sd_speed: num  4.06 4.55 3.82 10.96 3.28 ...      $ lap     : Factor w/ 2 levels "1","2": 1 1 1 1 1 1 1 1 1 1 ...  - attr(*, "vars")=List of 1   ..$ : symbol P  - attr(*, "drop")= logi TRUE 

I've read and tried everything and I really don't know how to fix it. It would be a pleasure if someone could help me!

This seems to be a bug associated with the 'tbl_df' format of your data frame. You can turn your data into a standard R data frame by using the function data.frame(). For example, right within the call to ezANOVA:

model<-ezANOVA(data=data.frame(RMdata)        ,dv=sd_speed        ,wid=P        ,within=c("Pr","lap")        ,type=3) 

Similar Posts:

Rate this post

Leave a Comment