If my dataset has columns like this
ID Group Col_item_01 Col_item_02 Col_item 03
1 Blue 11.23 10.12 4.3
2 Green 10.21 18.24 5.9
4 Purple 4.23 7.64 15.97
How can I convert all the columns starting with , Col_item_... to type numeric from character ? I know I can do this individually , df1$Col_item_01 <- as.numeric(as.character(df1$Col_item_01) but I am interested in an efficient approach using grep or grepl or string functions to extract just these columns starting with Col_item_... and changing them to numeric. Any suggestion is much appreciated. Thanks.
We may loop across the columns that starts_with 'Col_item_' and convert to numeric in tidyverse
library(dplyr)
df1 <- df1 %>%
mutate(across(starts_with("Col_item_"),
~ as.numeric(as.character(.))))
Or in base R, get the column names with pattern using grep and loop over the selected columns in lapply and do the assignment
nm1 <- grep("^Col_item_", names(df1))
df1[nm1] <- lapply(df1[nm1], function(x) as.numeric(as.character(x)))