如何用另一个变量中缺失值的累积和填充数据框

Question

Imagine you have the following data frame

x<- c(3, 5, 9, 12, 14)
y<- c(0.2, 0.4, 0.7, 1.4, 1.8)
df<- data.frame(x, y)
df

I asked a few months ago, how to fill "x" with remaining numbers and those numbers take the value zero in "y". And the answer was:

df <- tidyr::complete(df, x = 0:16, fill = list(y = 0))
cbind(df$x, df$y)

Now, I'd like to fill the numbers in the following way, but automatically, and I don't know if it is possible.
How to obtein "y1" automatically

Thanks in advance.

df$y1<- c(0,0,0, 0.2,0.2, 0.4,0.4,0.4,0.4, 0.7,0.7,0.7, 1.4,1.4, 1.8,1.8,1.8)
cbind(df$x, df$y1)

Answer 1

Instead of specifying the fill in complete , leave it as it is, so that by default it gets filled by NA , then use fill from tidyr to update the NA elements with the previous non-NA

library(dplyr)
library(tidyr)
tidyr::complete(df, x = 0:16) %>%
   fill(y, .direction = "down") %>% 
   mutate(y = replace(y, is.na(y), 0))

-output

# A tibble: 17 × 2
       x     y
   <dbl> <dbl>
 1     0   0  
 2     1   0  
 3     2   0  
 4     3   0.2
 5     4   0.2
 6     5   0.4
 7     6   0.4
 8     7   0.4
 9     8   0.4
10     9   0.7
11    10   0.7
12    11   0.7
13    12   1.4
14    13   1.4
15    14   1.8
16    15   1.8
17    16   1.8

Answer 2

df %>%
 complete(x=0:16) %>%
 fill(y) %>%
 replace_na(list(y=0))

# A tibble: 17 x 2
       x     y
   <dbl> <dbl>
 1     0   0  
 2     1   0  
 3     2   0  
 4     3   0.2
 5     4   0.2
 6     5   0.4
 7     6   0.4
 8     7   0.4
 9     8   0.4
10     9   0.7
11    10   0.7
12    11   0.7
13    12   1.4
14    13   1.4
15    14   1.8
16    15   1.8
17    16   1.8