## ## 可行的 x = sample(1:10, 25, replace=TRUE) y = 1+3*x xy = data.frame(x, y) colnames(xy) fit = lm(y~x, data=xy) ## ## 不可行 target <- "y" fit = lm(target~x, data=xy)
Standard input is empty
[1] "x" "y"
Error in model.frame.default(formula = target ~ x, data = xy, drop.unused.levels = TRUE) : variable lengths differ (found for 'x') Calls: lm -> eval -> eval -> <Anonymous> -> model.frame.default Execution halted