Replace NA values with value from another column in same dataframe

Question

I would like to replace NA in a particular column with values from another column in same dataframe

DF1:

Item    From    Price    Discount    NewPrice
 A     Delhi    100        .10         110
 A     Mumbai   200        .10         120
 A     Pune     150         NA          NA
 A     Nagpur   200        .10          NA

I would like to replace NA in NewPrice with the values in column Price

I have referred this but it is not helping Replace empty values with value from other column in a dataframe

Have tried below one but not working

df$NewPrice <- ifelse(df$NewPrice == "", df$Price, df$NewPrice)

Try `df$NewPrice <- ifelse(is.na(df$NewPrice), df$Price, df$NewPrice)` and see if that works — Andy Baxter, Jul 12 '19 at 08:11
In your linked post, the empty value is an empty string `""`, in your case it is `NA`, so we need to check for `is.na` as Andrew showed in above comment. — zx8754, Jul 12 '19 at 08:36

score 3 · Accepted Answer · answered Jul 12 '19 at 08:18

I would try with standard subsetting:

#subset the NAs of new price with the ones from price
df$NewPrice[is.na(df$NewPrice)] <- df$Price[is.na(df$NewPrice)]

Out:

df
#  Item   From Price Discount NewPrice
#1    A  Delhi   100      0.1      110
#2    A Mumbai   200      0.1      120
#3    A   Pune   150       NA      150
#4    A Nagpur   200      0.1      200

score 2 · Answer 2 · answered Jul 12 '19 at 08:24

2

tidyverse solution:

df %>% mutate(NewPrice=coalesce(NewPrice, Price))

answered Jul 12 '19 at 08:24

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Replace NA values with value from another column in same dataframe

2 Answers2