operating R dataframe using variables for the column name

Question

I want to store a column name in a variable and operate a dataframe based on that column name. For example if a I have two columns named car_sales and airplane_sales. I have a variable var that a user sets to say car_sales. i then calculate a new column like so:

calc_col <- paste0(var,"_delta")

df$calc_col <- abs(df$var - lag(df$var ,12))

The var will change based on user input, so the resulting column will also change

How do I do this in R?

score 1 · Accepted Answer · answered Jun 16 '22 at 14:03

1

You could use:

df[[calc_col]] <- abs(df[[var]] - lag(df[[var]], 12))

answered Jun 16 '22 at 14:03

harre

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Would this work if we want to use the dyplr filtering syntax too? Like `df %>% filter(df[[var]] == 1)` ? – thentangler Jun 16 '22 at 14:58

operating R dataframe using variables for the column name

1 Answers1