user9574337
user9574337

Reputation:

Move every n rows of a matrix to a new column in R

I have a data structure like the following

stat_names values

stat1       0.3
stat2       0.5

stat_x      ...


stat 16     0.8

and I would like to convert it to a similar structure, so that every 4 rows a new column is created and those 4 rows are moved to the new column.

  A     B     C     D
stat1 stat5 stat9  stat13
stat2 stat6 stat10 stat11`
 ...  ...   ...    ...

Where "A", "B", "C", "D" is a a-priori user-defined column names vector.

Although this is trivial to do by hand in Excel, I would like to do this in R with a script that can be iterated across multiple inputs.

Upvotes: 0

Views: 1296

Answers (1)

Dan
Dan

Reputation: 12084

Here, I cast the data frame as a matrix and then back to a data frame to produce the desired result.

# Dummy data frame
df <- data.frame(stat_names = paste("stat", 1:16, sep = " "),
                 values = runif(16))

# Cast as matrix with 4 rows and then as a data frame
df <- as.data.frame(matrix(df$stat_names, nrow = 4))

# Rename columns
names(df) <- LETTERS[1:ncol(df)]

#        A      B       C       D
# 1 stat 1 stat 5  stat 9 stat 13
# 2 stat 2 stat 6 stat 10 stat 14
# 3 stat 3 stat 7 stat 11 stat 15
# 4 stat 4 stat 8 stat 12 stat 16

If you actually want values in this format, change df$stat_names to df$values.

Upvotes: 2

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