Retain one column in a data frame as POSIXct and convert others to numeric in r-CodePudding

Leaving the date column I would like to convert rest of the columns in a data frame from chr to numeric. How could I achieve this? There are many columns in the data frame and below is only an extract. Thanks.

                 Date RECORD Battery_V Data_logger_Temp_C VWC_CS7
  2021-06-25 12:34:00      0     12.47              14.14   0.127

CodePudding user response：

Suppose we have the data frame shown reproducibly in the Note at the end. Then convert all columns except the first as shown. No packages are used.

DF2 <- replace(DF, -1, lapply(DF[-1], as.numeric))

DF2 <- DF
DF2[-1] <- lapply(DF2[-1], as.numeric)

or we can convert all character columns using:

ok <- sapply(DF, is.character)
DF2 <- replace(DF, ok, lapply(DF[ok], as.numeric))

DF2 <- DF
ok <- sapply(DF2, is.character)
DF2[ok] <- lapply(DF2[ok], as.numeric)

Note

Lines <- "                 Date RECORD Battery_V Data_logger_Temp_C VWC_CS7
  2021-06-25T12:34:00      0     12.47              14.14   0.127"
DF <- read.table(text = Lines, header = TRUE, colClasses = "character",
  strip.white = TRUE)
DF$Date <- as.POSIXct(DF$Date, format = "%Y-%m-%dT%H:%M:%S")

CodePudding user response：

library(dplyr)
df <- df %>% 
  mutate(across(.cols = -Date, as.numeric))