从一组数据帧中随机抽样

Question

我已根据各种条件创建了多个数据帧.现在我想对不同的数据帧进行采样,但是我想在采样后删除它们.我试过dplyrs sample_n:

sample_n(df, 4)

问题是这不会删除行,我是否需要一些递归循环,一旦它们被采样将删除行？或者是否有一些方便的功能可以帮助我？

Answer 1

适合我.

# generate data
a <- data.frame(letters = letters[1:5], var = rnorm(5))
b <- data.frame(letters = letters[6:10], var = rnorm(5))
c <- data.frame(letters = letters[11:15], var = rnorm(5))
xy <- list(a, b, c)

set.seed(357) # set seed for reproducibility
dfsample <- sample(seq_len(length(xy)), 1) # sample out one data.frame

xy[[dfsample]]

  letters         var
1       a  1.51348192
2       b -0.60657737
3       c  0.51828252
4       d -0.05352487
5       e -1.34303266

# remove random row, notice the minus sign in front of the sample
xy[[dfsample]] <- xy[[dfsample]][-sample(1:nrow(xy[[dfsample]]), 1), ]
xy[[dfsample]]

  letters         var
2       b -0.60657737
3       c  0.51828252
4       d -0.05352487
5       e -1.34303266