How To Add Columns To A Data Frame In R - R-bloggers

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The post How to add columns to a data frame in R appeared first on Data Science Tutorials

How to add columns to a data frame in R?, To add one or more columns to a data frame in R, use the mutate() function from the dplyr package.

With the following data frame, the following examples demonstrate how to use this syntax in practice.

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How to add columns to a data frame in R

Let’s create a data frame

df <- data.frame(player = c('P1', 'P2', 'P3', 'P4', 'P5', 'P6', 'P7'),                  points = c(122, 144, 154, 155, 120, 218, 229),                  assists = c(43, 55, 77, 18, 114, NA,29))

Now we can view the data frame

df     player points assists 1     P1    122      43 2     P2    144      55 3     P3    154      77 4     P4    155      18 5     P5    120     114 6     P6    218      NA 7     P7    229      29

Approach 1: Add Column at End of Data Frame

The following code demonstrates how to add a column to the data frame’s end.

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at the end of the data frame, add a ‘blocks’ column

df <- df %>%   mutate(score=c(1, 3, 3, 2, 4, 3, 6))

Let’s view the data frame

df player points assists score 1     P1    122      43     1 2     P2    144      55     3 3     P3    154      77     3 4     P4    155      18     2 5     P5    120     114     4 6     P6    218      NA     3 7     P7    229      29     6

It’s worth noting that you may create an empty column by just giving NA to each of the new column’s values.

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at the conclusion of the data frame, add an empty column

df <- df %>%         mutate(blocks=NA) df player points assists score 1     P1    122      43    NA 2     P2    144      55    NA 3     P3    154      77    NA 4     P4    155      18    NA 5     P5    120     114    NA 6     P6    218      NA    NA 7     P7    229      29    NA

Approach 2: Add Column Before Specific Column

The following code demonstrates how to insert a column in front of a certain column in a data frame:

insert the ‘score’ column after the ‘points’ column.

df <- df %>%         mutate(score=c(1, 3, 3, 2, 4, 3, 6),               .before=points) df player points assists score 1     P1    122      43     1 2     P2    144      55     3 3     P3    154      77     3 4     P4    155      18     2 5     P5    120     114     4 6     P6    218      NA     3 7     P7    229      29     6

Approach 3: Add Column After Specific Column

The following code demonstrates how to add a column to the data frame after a certain column.

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Following the ‘points’ column, add a ‘score’ column

df <- df %>%         mutate(blocks=c(1, 3, 3, 2, 4, 3, 6),               .after=points) df player points blocks assists score 1     P1    122      1      43     1 2     P2    144      3      55     3 3     P3    154      3      77     3 4     P4    155      2      18     2 5     P5    120      4     114     4 6     P6    218      3      NA     3 7     P7    229      6      29     6

Approach 4: Add Column Based on Other Columns

The following code demonstrates how to add a column in a data frame based on another column.

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add a ‘status’ column whose values are based on the ‘points’ column’s value

df <- df %>%         mutate(status= if_else(.$points > 20, 'Good', 'Bad')) df player points blocks assists score status 1     P1    122      1      43     1   Good 2     P2    144      3      55     3   Good 3     P3    154      3      77     3   Good 4     P4    155      2      18     2   Good 5     P5    120      4     114     4   Good 6     P6    218      3      NA     3   Good 7     P7    229      6      29     6   Good