如何在 R 中加入带有.x、.y 后缀的列

Question

我必须创建一个 dataframe ，其中包含特定日期期间传感器列表中的数据：

DATE                SENSOR1 SENSOR2 SENSOR3 SENSOR4
2020-04-20 00:00:00 1015    19.88   95.80   9.020 
2020-04-20 00:10:00 1015    19.84   96.10   8.970 
2020-04-20 00:20:00 1015    19.84   96.40   9.010 
2020-04-20 00:30:00 1015    19.81   96.60   9.210
2020-04-20 00:40:00 1015    19.79   96.80   9.700 
2020-04-20 00:50:00 1015    19.81   97.00   8.870

最初，我创建了一个 dataframe 1 列（ DATE ：包含指定日期之间所有日期的行，间隔为 10 分钟）。 通常它可以有数千行，但为了重现示例，我们可以保持简单：

periods <- data.frame(DATE = c("2020-04-20 00:00:00","2020-04-20 00:10:00","2020-04-20 00:20:00","2020-04-20 00:30:00","2020-04-20 00:40:00","2020-04-20 00:50:00"))

我有一个传感器列表 - > ID，所以在for 循环中我迭代所有传感器，查询我的数据库，从每个传感器返回 DATE 和 VALUE。 问题是，一个传感器可以有 2 个或多个 id，具体取决于数据存储的日期。

ID   SENSORNAME
1     SENSOR1 <- row that has data from SENSOR1 between 2020-04-20 00:00:00 and 2020-04-20 00:20:00
2     SENSOR2 ...
3     SENSOR3 ...
4     SENSOR4 ...
5     SENSOR1 <- row that has data from SENSOR1 between 2020-04-20 00:30:00 and 2020-04-20 00:50:00
6     SENSOR2 ...
7     SENSOR3 ...
8     SENSOR4 ...

原始代码：

for (i in 1:length(sensors$ID)) {
  sensor <- dbGetQuery(con, paste0("SELECT DATE, VALUE FROM MEASURES WHERE DATE between '2020-04-20 00:00:00' and '2020-04-20 00:50:00' AND ID= ",sensors$ID[i]," ORDER BY DATE ASC"))
  # getting rid of milliseconds
  sensor$DATE <- as.character(round_date(sensor$DATE, "minute"))
  # Renaming the column with sensor's name
  names(sensor) <- c("DATE", sensors$SENSORNAME[i])

  periods <- merge(periods,sensor,by="DATE",all = TRUE)  

  rm(sensor)
}

由于您无法查询我的数据库中的数据，因此可以通过手动创建 2 个 data.frames 来重现此示例

periods <- data.frame(DATE= c("2020-04-20 00:00:00","2020-04-20 00:10:00","2020-04-20 00:20:00","2020-04-20 00:30:00","2020-04-20 00:40:00","2020-04-20 00:50:00"), SENSOR1= c(1015, 1015, 1015, NA, NA, NA), SENSOR2= c(19.88, 19.84, 19.84, NA, NA, NA), SENSOR3= c(95.80, 96.10, 96.40, NA, NA, NA), SENSOR4= c(9.020, 8.970, 9.010, NA, NA, NA))
sensor <- data.frame(DATE= c("2020-04-20 00:00:00","2020-04-20 00:10:00","2020-04-20 00:20:00","2020-04-20 00:30:00","2020-04-20 00:40:00","2020-04-20 00:50:00"), SENSOR1= c(NA, NA, NA, 1010, 1010, 1010))

第 4 次迭代后，它开始在列名上添加后缀，如下所示：

DATE                SENSOR1.x SENSOR2.x SENSOR3.x SENSOR4.x SENSOR1.y SENSOR2.y SENSOR3.y SENSOR4.y
2020-04-20 00:00:00  1015      19.88     95.80     9.020      NA        NA        NA        NA
2020-04-20 00:10:00  1015      19.84     96.10     8.970      NA        NA        NA        NA 
2020-04-20 00:20:00  1015      19.84     96.40     9.010      NA        NA        NA        NA 
2020-04-20 00:30:00   NA        NA        NA        NA       1015      19.81     96.60     9.210
2020-04-20 00:40:00   NA        NA        NA        NA       1015      19.79     96.80     9.700 
2020-04-20 00:50:00   NA        NA        NA        NA       1015      19.81     97.00     8.870

关于如何正确合并或在生成 dataframe 后修复它的任何想法？

Answer 1

您可以使用pivot_longer中的tidyr将所有内容放在一个列中并在使用rbind将所有内容放回宽格式之前pivot_wider所有内容。 您还需要使用na.omit()删除 NA。

library(tidyr)
periods %>%
  pivot_longer(-DATE) %>%
  rbind(sensor %>%
              pivot_longer(-DATE) ) %>%
  na.omit() %>%
  pivot_wider(names_from = name, values_from = value) 

Joining, by = c("DATE", "name", "value")
# A tibble: 6 x 5
  DATE                SENSOR1 SENSOR2 SENSOR3 SENSOR4
  <fct>                 <dbl>   <dbl>   <dbl>   <dbl>
1 2020-04-20 00:00:00    1015    19.9    95.8    9.02
2 2020-04-20 00:10:00    1015    19.8    96.1    8.97
3 2020-04-20 00:20:00    1015    19.8    96.4    9.01
4 2020-04-20 00:30:00    1010    NA      NA     NA   
5 2020-04-20 00:40:00    1010    NA      NA     NA   
6 2020-04-20 00:50:00    1010    NA      NA     NA 

数据

periods <- data.frame(DATE= c("2020-04-20 00:00:00","2020-04-20 00:10:00","2020-04-20 00:20:00","2020-04-20 00:30:00","2020-04-20 00:40:00","2020-04-20 00:50:00"), SENSOR1= c(1015, 1015, 1015, NA, NA, NA), SENSOR2= c(19.88, 19.84, 19.84, NA, NA, NA), SENSOR3= c(95.80, 96.10, 96.40, NA, NA, NA), SENSOR4= c(9.020, 8.970, 9.010, NA, NA, NA))
sensor <- data.frame(DATE= c("2020-04-20 00:00:00","2020-04-20 00:10:00","2020-04-20 00:20:00","2020-04-20 00:30:00","2020-04-20 00:40:00","2020-04-20 00:50:00"), SENSOR1= c(NA, NA, NA, 1010, 1010, 1010))