It is a little difficult to answer your specific question without a full, reproducible example. However something like this should work:
#Turn your 'treatment' column into a character vector
data$Treatment <- as.character(data$Treatment)
#Then turn it back into a factor with the levels in the correct order
data$Treatment <- factor(data$Treatment, levels=unique(data$Treatment))
In this example, the order of the factor will be the same as in the data.csv
file.
If you prefer a different order, you can order them by hand:
data$Treatment <- factor(data$Treatment, levels=c("Y", "X", "Z"))
However this is dangerous if you have a lot of levels: if you get any of them wrong, that will cause problems.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…