How to fix ‘Error in FUN(X[[i]], …) : only defined on a data frame with all numeric variables”

Question

I intend to draw a qq plot on the data, but it reminds me that qqnorm function only works on numerical data.

As the factor include A,B,C,D and their two, three and four way interaction, I have no idea how to convert it into numerical form.

The data is as follows:

Effects,Value
A,76.95
B,-67.52
C,-7.84
D,-18.73
AB,-51.32
AC,11.69
AD,9.78
BC,20.78
BD,14.74
CD,1.27
ABC,-2.82
ABD,-6.5
ACD,10.2
BCD,-7.98
ABCD,-6.25

My code is as follows:

library(readr)
data621 <- read_csv("Desktop/data621.csv")
data621_qq<-qqnorm(data621,xlab = "effects",datax = T)
qqline(data621,probs=c(0.3,0.7),datax = T)
text(data621_qq$x,data621_qq$y,names(data621),pos=4)

Answer 1

Your code would work if using the proper columns instead of the entire data frame. For example,

data621_qq <- qqnorm(data621$Value, xlab = "Effects", datax = TRUE)
qqline(data621$Value, probs = c(0.3, 0.7), datax = TRUE)
text(data621_qq$x, data621_qq$y, data621$Effects, pos=4)

By the way, names(data621) would give you the column names, instead of the effect names (which are stored as values in a column).