我正在使用dplyr将一些数据简单地分成训练集和测试集。
当我进行简单例子时,它非常有效:
当我进行简单例子时,它非常有效:
a = c(1, 2, 3, 4, 5, 6, 7, 8)
b = c("A", "B", "C", "D", "E", "F", "G", "H")
df = data.frame(a, b)
train = sample_frac(df, 0.8)
test = setdiff(df, train)
> nrow(train) + nrow(test) == nrow(df)
[1] TRUE
然而,当我尝试使用经典的UCI Wine数据集进行相同操作时,似乎无法得到相同的结果:
wine = read.csv("http://www.nd.edu/~mclark19/learn/data/goodwine.csv")
wine_train = sample_frac(wine, 0.8)
wine_test = setdiff(wine, wine_train)
> nrow(wine_train) + nrow(wine_test) == nrow(wine)
[1] FALSE
> nrow(wine_train) + nrow(wine_test)
[1] 6105
> nrow(wine)
[1] 6497
我是否忽略了setdiff的某些行为?
谢谢, AG