kableExtra: Dynamic add_header_above labeling

Question

I would like to create a pdf with rmarkdown. The PDF should contain a table. The table should have a dynamic column label.

The tabhead should display the calendar week.

However, the calendar week (e.g., KW29) is not displayed but the variable name "kw0".

What is my error?

library(knitr)
library(kableExtra)
library(lubridate)
options(knitr.table.format = "latex")
loadData <- function() {# load some data}

myData<- loadData ()

kw0 <- paste("KW", week(Sys.Date()) - 1, sep = "")
kw1 <- paste("KW", week(Sys.Date()), sep = "")
kw2 <- paste("KW", week(Sys.Date()) + 1, sep = "")
kw3 <- paste("KW", week(Sys.Date()) + 2, sep = "")


kable(myData, row.names = FALSE, booktabs = T) %>%
  kable_styling(
  full_width = TRUE,
  font_size = 14 
  )  %>% add_header_above(header = c(" " = 1, kw0 = 2, kw1 = 2, kw2 = 2, kw3 = 2))

I am glad about your advice.

Possessory

Answer 1

To create a dynamic header, use a named character vector with colspan(s) as values.

You can assign names to the vector with the function names():

library(knitr)
library(kableExtra)
library(lubridate)
options(knitr.table.format = "latex")

loadData <- function() {# load some data}

myData<- loadData()

kw0 <- paste("KW", week(Sys.Date()) - 1, sep = "")
kw1 <- paste("KW", week(Sys.Date()), sep = "")
kw2 <- paste("KW", week(Sys.Date()) + 1, sep = "")
kw3 <- paste("KW", week(Sys.Date()) + 2, sep = "")
    
# create vector with colspans
myHeader <- c(1, 2, 2, 2, 2)

# set vector names 
names(myHeader) <- c(" ", kw0, kw1, kw2, kw3)

# Assign dynamic named vector
kable(myData, row.names = FALSE, booktabs = T) %>%
  kable_styling(
    full_width = TRUE,
    font_size = 14 
  ) %>% 
  add_header_above(header = myHeader)

Possessory

myHeader <- c(2, 2, 2) and names(myHeader) <- c("n1", "n2", "n3") – Francesfrancesca

Answer 2

An easy and quick method using setNames() is described on the kableExtra developer's github page: https://github.com/haozhu233/kableExtra/issues/415

library(knitr)
library(kableExtra)
library(lubridate)
options(knitr.table.format = "latex")

loadData <- function() { # load some data
}

myData<- loadData()

kw0 <- paste("KW", week(Sys.Date()) - 1, sep = "")
kw1 <- paste("KW", week(Sys.Date()), sep = "")
kw2 <- paste("KW", week(Sys.Date()) + 1, sep = "")
kw3 <- paste("KW", week(Sys.Date()) + 2, sep = "")

kable(myData, row.names = FALSE, booktabs = T) %>%
  kable_styling(
    full_width = TRUE,
    font_size = 14 
  ) %>% 
add_header_above(header = c(" " = 1, 
                            setNames(2,kw0), 
                            setNames(2,kw1), 
                            setNames(2,kw2), 
                            setNames(2,kw3))

Haws