How do I work with multiple line headers in R?-CodePudding

I have the following data frame:

fruit <- c("What is your favorite fruit?", "apple", "grape", "lemon")
color <- c("What is the color of the fruit?", "red", "purple", "yellow")
taste <- c("How does the fruit taste?", "sweet", "sweet", "sour")

df <- data.frame(fruit, color, taste)
View(df)

I want the first two rows to be the headers.

Ideally, I want to be able to add a column called "number" and have it not have a second row header. I want something that looks like this:

df <- df %>%
  mutate(
    number = c(NA, 3, 7, 8)
  )

But I don't want to have to add the NA there. Preferably, I can just do this:

df <- df %>%
  mutate(
    number = c(3, 7, 8)
  )

And get the same df and without getting the Error in `mutate()`:! Problem while computing `number = c(3, 7, 8)`. ✖ `number` must be size 4 or 1, not 3. error.

In Excel, I can just hide the second row. Is there a "hide" option in R?

CodePudding user response：

As r2evens suggested, survey questions are often stored as labels. If your primary objective is how to preserve the data elements, you can also consider using a list. Keep your data in a data frame as one element in the list, and the questions as a vector and another element of the list.

So consider df as your dataframe and question as your vector of questions.


number <- c(3,7,8)
fruit <- c("apple", "grape", "lemon")
color <- c("red", "purple", "yellow")
taste <- c("sweet", "sweet", "sour")

df <- data.frame(number, fruit, color, taste)

question <- c("What is your favorite fruit?", "What is the color of the fruit?", "How does the fruit taste?")

You can then combine them into a named list.

myList <- list(df = df, question = question)

Not very pretty

> myList
$df
  number fruit  color taste
1      3 apple    red sweet
2      7 grape purple sweet
3      8 lemon yellow  sour

$question
[1] "What is your favorite fruit?"    "What is the color of the fruit?" "How does the fruit taste?"

But when you want to just see the data you can do this.

> myList$df
  number fruit  color taste
1      3 apple    red sweet
2      7 grape purple sweet
3      8 lemon yellow  sour

And in those cases you need the questions, you can call on them. In this case, I replace the field names with the question, but I have to remove the number column first unless I put in a place holder for that column.

myListQ <-myList$df[-1] 
names(myListQ) <- myList$question
myListQ

> myListQ
  What is your favorite fruit? What is the color of the fruit? How does the fruit taste?
1                        apple                             red                     sweet
2                        grape                          purple                     sweet
3                        lemon                          yellow                      sour

CodePudding user response：

Base R solution:

# Rename the data.frame's vectors and add the 
# the number column: result_df => data.frame
result_df <- within(
  setNames(
    df[-1,],
    df[1,]
  ),
  {
    number = c(3, 7, 8)
  }
)

# Print the result to the console: 
# data.frame => stdout(console)
result_df