计算数据框中跨列的最长连续序列 - R

Question

我有一个如下所示的数据框...

df <- data.frame(B1994 = c(1,0,0,0,1,0,0,1,1,0),
                 B1995 = c(1,1,1,0,0,1,1,1,0,0),
                 B1996 = c(0,0,0,0,0,0,1,1,1,0),
                 B1997 = c(1,0,1,0,0,1,0,1,1,1),
                 B1998 = c(1,0,0,0,1,0,1,0,0,1)
)

我现在正在尝试计算此数据框中所有列（每一行）的最长连续 0 序列，并使用这些值填充新列，如下面的数据框...

df2 <- data.frame(B1994 = c(1,0,0,0,1,0,0,1,1,0),
                 B1995 = c(1,1,1,0,0,1,1,1,0,0),
                 B1996 = c(0,0,0,0,0,0,1,1,1,0),
                 B1997 = c(1,0,1,0,0,1,0,1,1,1),
                 B1998 = c(1,0,0,0,1,0,1,0,0,1),
                 Longest_0_Interval = c(1,3,1,5,3,1,1,1,1,3)
)

在 R 中对此有简单的解决方案吗？

Answer 1

一个dplyr选项可以是：

df %>%
 rowwise() %>%
 mutate(Longest_0_Interval = with(rle(c_across(everything())), max(lengths[values == 0])))

   B1994 B1995 B1996 B1997 B1998 Longest_0_Interval
   <dbl> <dbl> <dbl> <dbl> <dbl>              <int>
 1     1     1     0     1     1                  1
 2     0     1     0     0     0                  3
 3     0     1     0     1     0                  1
 4     0     0     0     0     0                  5
 5     1     0     0     0     1                  3
 6     0     1     0     1     0                  1
 7     0     1     1     0     1                  1
 8     1     1     1     1     0                  1
 9     1     0     1     1     0                  1
10     0     0     0     1     1                  3

Answer 2

您可以使用rle()

df <- data.frame(B1994 = c(1,0,0,0,1,0,0,1,1,0),
                 B1995 = c(1,1,1,0,0,1,1,1,0,0),
                 B1996 = c(0,0,0,0,0,0,1,1,1,0),
                 B1997 = c(1,0,1,0,0,1,0,1,1,1),
                 B1998 = c(1,0,0,0,1,0,1,0,0,1)
)

maxl0 <- function(x) {
  r <- rle(x)
  i0 <- which(r$values==0)  ## or i0 <- r$values==0
  max(r$lengths[i0])
}

df$Longest_0_Interval <- apply(df, 1, maxl0)

计算数据框中跨列的最长连续序列 - R

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r

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