gg_chunk in footer/header

[okeep]

I'm wondering if it is possible to add a ggplot/gg_chunk to a footer cell specifically (although I imagine it would likely work and be useful for headers as well). I've been able to add figures to the body easily enough, but using similar code in the footer doesn't appear to work.

This is a simplified version of my current code. I'd like to move the figure created in the second mk_par statement into the footer:

temp=data.table(estimate=rnorm(10))
temp[,`:=`(
    lower.CL=estimate-1,
    upper.CL=estimate+1)]

axis_plot=ggplot(data=NULL, aes(x=rnorm(1), y=rnorm(1)))+geom_point()

temp[,` `:=list(list(ggplot(data.table(estimate, lower.CL, upper.CL), aes(x=1, y=estimate, ymin=lower.CL, ymax=upper.CL))+geom_point()+geom_errorbar())), by=1:nrow(temp)]
plots=list(temp$` `)
temp=rbindlist(list(temp, data.table(` `=list(axis_plot))), fill=T)

tab=flextable(temp)|>
    colformat_double(digits=3)|>
    mk_par(j=" ", i=1:(nrow(temp)-1),
           value=as_paragraph(gg_chunk(value=., height=1, width=2)),
           use_dot = T)|>
    mk_par(j=" ", i=nrow(temp),
           value=as_paragraph(gg_chunk(value=list(axis_plot), height=1, width=2)))

[davidgohel]

You can almost always do in footer or header what you can do in body, there is an argument in several functions named part, it can have values 'header', 'footer' and 'body'. If you use for example mk_par(), it supports this argument.

However, in your case, as there is no row in footer yet (there is no footer by default), it is far easier to use add_footer_lines().

library(flextable)
library(ggplot2)
library(data.table)

temp <- data.table(estimate = rnorm(10))

temp[, `:=`(
  lower.CL = estimate - 1,
  upper.CL = estimate + 1
)]

axis_plot <- ggplot(data = NULL, aes(x = rnorm(1), y = rnorm(1))) +
  geom_point()

temp[, ` ` := list(list(ggplot(data.table(estimate, lower.CL, upper.CL), aes(x = 1, y = estimate, ymin = lower.CL, ymax = upper.CL)) +
  geom_point() +
  geom_errorbar())), by = 1:nrow(temp)]
plots <- list(temp$` `)
temp <- rbindlist(list(temp, data.table(` ` = list(axis_plot))), fill = T)

tab <- flextable(temp) |>
  colformat_double(digits = 3) |>
  mk_par(
    j = " ", i = 1:(nrow(temp) - 1),
    value = as_paragraph(gg_chunk(value = ., height = 1, width = 2)), use_dot = TRUE) |>
  add_footer_lines(as_paragraph(gg_chunk(value = list(axis_plot), height = 1, width = 2)))

tab

You can learn more about flextable design here: https://ardata-fr.github.io/flextable-book/table-design.html

[okeep]

Ah, that helps, somewhat.

A final question: is there a way to make the figures line up? I had tried using add_footer_row() previously (in the same way you're using add_footer_lines()), but got this error: Error in inverse.rle(structure(list(lengths = colwidths, values = values), : invalid 'rle' structure

[davidgohel]

library(flextable)
library(ggplot2)
library(data.table)

temp <- data.table(estimate = rnorm(10))

temp[, `:=`(
  lower.CL = estimate - 1,
  upper.CL = estimate + 1
)]

axis_plot <- ggplot(data = NULL, aes(x = rnorm(1), y = rnorm(1))) +
  geom_point()

temp[, ` ` := list(list(ggplot(data.table(estimate, lower.CL, upper.CL), aes(x = 1, y = estimate, ymin = lower.CL, ymax = upper.CL)) +
                          geom_point() +
                          geom_errorbar())), by = 1:nrow(temp)]

tab <- flextable(temp) |>
  colformat_double(digits = 3) |>
  mk_par(
    j = " ", 
    value = as_paragraph(gg_chunk(value = ., height = 1, width = 2)), use_dot = TRUE) |>
  add_footer( ` ` = "") |> 
  mk_par(part = "footer", i = 1, j = " ", 
         value = as_paragraph(gg_chunk(value = list(axis_plot), height = 1, width = 2)))

tab

[okeep]

Thanks, this was very helpful.