knitr的spin（）：不能在标题中嵌入内联R表达式

Question

I'm using knitr 's spin() function to render an R script to HTML (using RStudio's "Compile Notebook" command).

While it's easy to include a dynamic R expression in plain text, this apparently does not work for a heading.

For example, this first example correctly embeds an inline expression into plain text:

library(knitr)

#' You can use the special syntax {{code}} to embed inline expressions, e.g.
{{mean(x) + 2}}
#' is the mean of x plus 2.

But this second example, when rendering HTML, only applies the heading style to the first line ("Crosstabulation of"), and then wraps the line and reverts back to plain text:

library(knitr)
var0 <- "Sex"
var1 <- "Education"

#' # Crosstabulation of
{{var0}}
#' # by
{{var1}}
#' # .

How can I have the heading style applied to all the lines of the chunk? Is there any alternative syntax I have to use? What am I missing?

Answer 1

I think it's a limitation of spin() . You could pre-process the file with brew , or get R to output the header in markdown,

`%#%` <- function(tpl, vals) if(interactive()) vals else do.call(sprintf, c(fmt=tpl, vals)) 

var0 <- "Sex"
var1 <- "Education"

{{"# Crosstabulation of %s by %s " %#% list(var0, var1)}}