r语言 - IF else按下一行的组检查值

Question

这是一个df，例如:

test_df <- structure(list(plant_sp = c("plant_1", "plant_1", "plant_2", "plant_2", "plant_3",
"plant_3", "plant_3", "plant_3", "plant_3", "plant_4", 
"plant_4", "plant_4", "plant_4", "plant_4", "plant_4",
"plant_5", "plant_5", "plant_5", "plant_5", "plant_5"), 
sp_rich = c(1, 1, NA, 1, NA, 
1, 0, 0, NA, 0,
0, 1, 0, 0, 1, 
0, NA, NA, 0,NA)), 
row.names = c(NA, -20L), class = "data.frame", 
.Names = c("plant_sp", "sp_rich"))

我正在尝试创建一个使用tidyverse的ifelse语句:每组按"plant_sp"检查列"sp_rich"中的值is.na如果是，则设置value "1"在名为"is_na_nest_row"的新列中。我设法做到了以下几点:

test_df %>%
group_by(plant_sp) %>%
mutate(is_na_nest_row = ifelse(???,1,0))

但我不知道如何在列sp_rich中引用值，但在下一行(中的组))

例如:

我想要值"1"若第3行is_na_nest_row下有空行，则第4行sp_rich下有空行

非常感谢。被罩

Answer 1

编辑:现在应该可以正常工作了。

您可以通过在mutate中使用row_number()访问下一行。所以我认为这是正确的解决方案。

test_df %>% group_by(plant_sp) %>% mutate(Test = ifelse(is.na(sp_rich[row_number() + 1]), 1, 0),  Test = c(Test[-n()], 0)))

与输出

# A tibble: 20 x 3
# Groups:   plant_sp [5]
plant_sp sp_rich  Test
<chr>      <dbl> <dbl>
1 plant_1        1     0
2 plant_1        1     0
3 plant_2       NA     0
4 plant_2        1     0
5 plant_3       NA     0
6 plant_3        1     0
7 plant_3        0     0
8 plant_3        0     1
9 plant_3       NA     0
10 plant_4        0     0
11 plant_4        0     0
12 plant_4        1     0
13 plant_4        0     0
14 plant_4        0     0
15 plant_4        1     0
16 plant_5        0     1
17 plant_5       NA     1
18 plant_5       NA     0
19 plant_5        0     1
20 plant_5       NA     0

Answer 2

test_df %>%
group_by(plant_sp) %>%
mutate(is_na_nest_row = +any(is.na(sp_rich)))
# # A tibble: 20 x 3
# # Groups:   plant_sp [5]
#    plant_sp sp_rich is_na_nest_row
#    <chr>      <dbl>          <int>
#  1 plant_1        1              0
#  2 plant_1        1              0
#  3 plant_2       NA              1
#  4 plant_2        1              1
#  5 plant_3       NA              1
#  6 plant_3        1              1
#  7 plant_3        0              1
#  8 plant_3        0              1
#  9 plant_3       NA              1
# 10 plant_4        0              0
# 11 plant_4        0              0
# 12 plant_4        1              0
# 13 plant_4        0              0
# 14 plant_4        0              0
# 15 plant_4        1              0
# 16 plant_5        0              1
# 17 plant_5       NA              1
# 18 plant_5       NA              1
# 19 plant_5        0              1
# 20 plant_5       NA              1

或者如果只是下一行，

test_df %>%
group_by(plant_sp) %>%
mutate(is_na_nest_row = +(lead(is.na(sp_rich), default = FALSE)))
# # A tibble: 20 x 3
# # Groups:   plant_sp [5]
#    plant_sp sp_rich is_na_nest_row
#    <chr>      <dbl>          <int>
#  1 plant_1        1              0
#  2 plant_1        1              0
#  3 plant_2       NA              0
#  4 plant_2        1              0
#  5 plant_3       NA              0
#  6 plant_3        1              0
#  7 plant_3        0              0
#  8 plant_3        0              1
#  9 plant_3       NA              0
# 10 plant_4        0              0
# 11 plant_4        0              0
# 12 plant_4        1              0
# 13 plant_4        0              0
# 14 plant_4        0              0
# 15 plant_4        1              0
# 16 plant_5        0              1
# 17 plant_5       NA              1
# 18 plant_5       NA              0
# 19 plant_5        0              1
# 20 plant_5       NA              0