I keep getting the error "is.numeric(x) is not TRUE" even though I performed a class check on my data and it is numeric. I am trying to perform a shapiro test to check for normality. My data has 5 columns: "id" (participant id), "realorsham" (my group column - contains 2 groups), "CR1", "CR15", and "CR16" (scores from questionnaire taken on 3 different days). All of my data is numeric but whenever I use the shapiro.test function I get that error. Any advice? I tried converting the data to be numeric and used the sapply function to test for class, which all came back numeric for the columns I was testing. Can anyone give me any insight?
