我需要用组中以前的非 NaN 值替换 NaN 值。
这是一个例子:
+-------+------------+-------+
| ts_id | date | value |
+-------+------------+-------+
| 2 | 01/10/2014 | 18 |
| 2 | 01/11/2014 | 15 |
| 2 | 01/12/2014 | NaN |
| 2 | 01/01/2015 | NaN |
| 2 | 01/02/2015 | NaN |
| 3 | 01/03/2015 | 19 |
| 3 | 01/04/2015 | 20 |
| 3 | 01/10/2015 | 12 |
| 3 | 01/11/2015 | 17 |
| 3 | 01/12/2015 | NaN |
| 3 | 01/01/2016 | NaN |
| 3 | 01/08/2016 | 7 |
| 3 | 01/09/2016 | NaN |
| 3 | 01/10/2016 | NaN |
| 3 | 01/11/2016 | NaN |
| 3 | 01/12/2016 | NaN |
| 3 | 01/01/2017 | NaN |
+-------+------------+-------+
数据:
data <- structure(list(ts_id = c(2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3), date = structure(c(16344, 16375, 16405, 16436,
16467, 16495, 16526, 16709, 16740, 16770, 16801, 17014, 17045,
17075, 17106, 17136, 17167), class = "Date"), value = c(18, 15,
NaN, NaN, NaN, 19, 20, 12, 17, NaN, NaN, 7, NaN, NaN, NaN, NaN,
NaN)), row.names = c(NA, -17L), vars = "ts_id", drop = TRUE, indices = list(
0:16), group_sizes = 17L, biggest_group_size = 17L, labels = structure(list(
ts_id = 3L), row.names = c(NA, -1L), class = "data.frame", vars = "ts_id", drop = TRUE), class = "data.frame")
在每个组中(由 ts_id 标识)，我可以在任何给定日期拥有 NaN 值。我需要用最近的非 NaN 值替换每个 NaN。
结果应如下所示:
+-------+------------+-------+
| ts_id | date | value |
+-------+------------+-------+
| 2 | 01/10/2014 | 18 |
| 2 | 01/11/2014 | 15 |
| 2 | 01/12/2014 | 15 |
| 2 | 01/01/2015 | 15 |
| 2 | 01/02/2015 | 15 |
| 3 | 01/03/2015 | 19 |
| 3 | 01/04/2015 | 20 |
| 3 | 01/10/2015 | 12 |
| 3 | 01/11/2015 | 17 |
| 3 | 01/12/2015 | 17 |
| 3 | 01/01/2016 | 17 |
| 3 | 01/08/2016 | 7 |
| 3 | 01/09/2016 | 7 |
| 3 | 01/10/2016 | 7 |
| 3 | 01/11/2016 | 7 |
| 3 | 01/12/2016 | 7 |
| 3 | 01/01/2017 | 7 |
+-------+------------+-------+
提前致谢。
最佳答案
你可以用这个:
library(dplyr)
library(zoo) # for the na.locf function
data %>%
group_by(ts_id) %>% # group by id
mutate(value = na.locf(value,na.rm=F)) # na.locf fills with the last non-empty value
#head()
# # A tibble: 6 x 3
# # Groups: ts_id [2]
# ts_id date value
# <dbl> <date> <dbl>
# 1 2 2014-10-01 18
# 2 2 2014-11-01 15
# 3 2 2014-12-01 15
# 4 2 2015-01-01 15
# 5 2 2015-02-01 15
# 6 3 2015-03-01 19
关于r - 如何用组内以前的非 NaN 替换 NaN 值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/53210281/