将列扩展为R中的日期

Question

I have data structured in the following way:

• date H01 H02 ... H48

• 01-Jan-19 15,328 15,273 ... 5,241

• 02-Jan-19 17,412 17,474 ... 7,625

H01 to H48 represent values each 30 min within the same day. This does not follow the principles of tidy data.

I would like to have only two columns:

• date value
• 01/01/2019 00:00 15,328
• 01/01/2019 00:30 15,273
• 01/01/2019 01:00 ...

How can I obtain this in R?

Thank you!

Answer 1

The package tidyr makes this pretty easy with the gather function.

library(dplyr)
library(tidyr)

df <- tibble(Date = c("01-Jan-19", "02-Jan-19"),
             H01 = c(15328, 17412),
             H02 = c(15273, 17474))

times.df <- tibble(Code = c("H01", "H02"),
                       Time = c("00:30", "1:00"))

gather(df, key = "Code", value = "Value", -Date) %>%
  left_join(times.df) %>%
  mutate(DateTime = dmy_hm(paste(Date, Time, sep = " "))) 

# Joining, by = "Code"
# # A tibble: 4 x 5
# Date      Code  Value Time  DateTime           
# <chr>     <chr> <dbl> <chr> <dttm>             
#   1 01-Jan-19 H01   15328 00:30 2019-01-01 00:30:00
# 2 02-Jan-19 H01   17412 00:30 2019-01-02 00:30:00
# 3 01-Jan-19 H02   15273 1:00  2019-01-01 01:00:00
# 4 02-Jan-19 H02   17474 1:00  2019-01-02 01:00:00