r - 如何从 R 数据框的两列中联合采样？

Question

我有一个 4 列的数据框。我正在尝试将数据框的两列混在一起，以使这两列始终相关。

我已经尝试过“示例”功能，但它仅限于一列数据框。

data = data.frame(label=letters[1:5], label2=letters[1:15], number=11:15)
data = within(data, numbersq <- (number*number))

# lable lable2 number numbersq
#   a     a      11     121
#   b     b      12     144
#   c     c      13     169
#   d     d      14     196
#   e     e      15     225

#Now, I want to twick the data something like, columns 'lable' and 'lable2' remains as it is and columns 'number' and 'numbersq' should shufffle. 
#As you can see in the desired output,'number' and 'numbersq' should shuffled together not separately.

#Desired Output

# lable lable2 number numbersq
#   a     a      15     225
#   b     b      13     169
#   c     c      14     196
#   d     d      12     144
#   e     e      11     121

I have tried he following code but seems it shuffles the columns separately.

data_2 = data.frame(data_2$label, data_2$label2, sample(data_2$number), sample(data_2$numbersq))

标签： rshufflesample

Answer 1

非常感谢您的建议。最后我得到了解决方案。代码如下。我相信代码仍然可以优化。

data <- data.frame(label=letters[1:5], lable2=letters[1:5], number=11:15)
data = within(data, numbersq <- (number*number))
print(data)

# lable lable2 number numbersq
#   a     a      11     121
#   b     b      12     144
#   c     c      13     169
#   d     d      14     196
#   e     e      15     225


data_2a = data[,1:2]
data_2b = data[,3:4]
data_2b_samp = data_2b[sample(nrow(data_2b)), ]

data_3 = cbind(data_2a, data_2b_samp)

print(data_3)

# lable lable2 number numbersq
#   a     a      15     225
#   b     b      13     169
#   c     c      14     196
#   d     d      12     144
#   e     e      11     121