Question

我正在尝试每小时提取0到40分钟之间的所有变量的平均值。

dput(head(df))

structure(list(DateTime = structure(c(1563467460, 1563468060, 
1563468660, 1563469260, 1563469860, 1563470460), class = c("POSIXct", 
"POSIXt"), tzone = "GMT"), date = structure(c(1563467460, 1563468060, 
1563468660, 1563469260, 1563469860, 1563470460), class = c("POSIXct", 
"POSIXt"), tzone = "GMT"), Date = structure(c(18095, 18095, 18095, 
18095, 18095, 18095), class = "Date"), TimeCtr = structure(c(1563467460, 
1563468060, 1563468660, 1563469260, 1563469860, 1563470460), class = c("POSIXct", 
"POSIXt"), tzone = "GMT"), MassConc = c(0.397627, 0.539531, 0.571902, 
0.608715, 0.670382, 0.835773), VolConc = c(175.038, 160.534, 
174.386, 183.004, 191.074, 174.468), NumbConc = c(234.456, 326.186, 
335.653, 348.996, 376.018, 488.279), MassD = c(101.426, 102.462, 
101.645, 102.145, 101.255, 101.433)), .Names = c("DateTime", 
"date", "Date", "TimeCtr", "MassConc", "VolConc", "NumbConc", 
"MassD"), row.names = c(NA, 6L), class = "data.frame")

到目前为止，我已经尝试过了。

 hourly_mean<-mydata %>% 
  filter(between(as.numeric(format(DateTime, "%M")), 0, 40)) %>% 
  group_by(DateTime=format(DateTime, "%Y-%m-%d %H")) %>%
  summarise(variable1_mean=mean(variable1))

但是它给了我整个时期的平均值。任何帮助都非常欢迎。

Answer 1

我们可以转换DateTime，以小时单位使用ceiling_date舍入Datetime，从DateTime和filter中提取分钟数，以保持小于40，group_by hour并取mean个值。

library(lubridate)
library(dplyr)

df %>%
  dplyr::mutate(DateTime = ymd_hm(DateTime), 
         hour = ceiling_date(DateTime, "hour"),  
         minutes =  minute(DateTime)) %>%
  filter(minutes <= 40) %>%
  group_by(hour) %>%
  summarise_at(vars(ends_with("Conc")), mean)

数据

df <- structure(list(DateTime = structure(1:7, .Label = c("2019-08-0810:07", 
"2019-08-0810:17", "2019-08-0810:27", "2019-08-0810:37", "2019-08-0810:47", 
"2019-08-0810:57", "2019-08-0811:07"), class = "factor"), MassConc = c(0.556398, 
1.06868, 0.777654, 0.87289, 0.789704, 0.51948, 0.416676), NumbConc = c(588.069, 
984.018, 964.634, 997.678, 1013.52, 924.271, 916.357), VolConc = c(582.887, 
979.685, 963.3, 994.178, 1009.52, 922.104, 916.856), Conc = c(281.665, 
486.176, 420.058, 422.101, 429.841, 346.539, 330.282)), class = 
"data.frame", row.names = c(NA, -7L))

r中特定时间范围的平均时间

1 个答案: