Group/Merge values as header in flextable

I have a dataset similar to this

mydf<-data.frame(
  estimate=rep(c("b0","b1","b2"),2),
  linear=rep(c("0.1(0.1)*","0.1(0.1)*",""),2),
  quadratic=rep(c("0.1(0.1)*","0.1(0.1)*","0.1(0.1)*"),2),
  zone=c(rep("A",3),rep("B",3))
)

I would like to create a flextable similar to this pivot_wider result but with the columns linear and quadratic merged for each zone

mydf%>%
pivot_wider(names_from=zone,values_from=c(linear,quadratic))

The function merge_v does it by row, but what I need is to put the merged cells as merged headers.

Solution

There are various methods for that, I like this one because it works well with dplyr/tidyr:


mydf<-data.frame(
  estimate=rep(c("b0","b1","b2"),2),
  linear=rep(c("0.1(0.1)*","0.1(0.1)*",""),2),
  quadratic=rep(c("0.1(0.1)*","0.1(0.1)*","0.1(0.1)*"),2),
  zone=c(rep("A",3),rep("B",3))
)

mydf%>%
  pivot_wider(names_from=zone,values_from=c(linear,quadratic)) |> 
  flextable::flextable() |> 
  flextable::separate_header() |> 
  flextable::align(align = "center", part = "all")