Suppose there is a code chunk as follows:
```{r mean diff}
(5-mean(dnorm(40,5,2))/5
```
I would like to be able to reference this code chunk with its label in inline form in a markdown document, so that the reference is replaced by the output of this chunk. Is there a way to do it?
" the difference is `r mean diff` %." ##something like this?
I think the answer to your question is "yes, but it's tricky". By default knitr doesn't save the last value computed in a code chunk. In regular code, the last value calculated is saved in .Last.value, but knitr doesn't simulate this.
However, a simple modification lets you do something very similar:
```{r}
meandiff <- 5-mean(dnorm(40,5,2))/5
meandiff # if you want the chunk to print its value
```
and then in the text, use
" the difference is `r meandiff` %."
If you really want to save the last value, it's possible by setting a "render hook". For example, the code below saves the last value, then calls the old hook:
```{r}
.Last.value <- NULL
old_hook <- knitr::opts_chunk$get("render")
knitr::opts_chunk$set(render = function(x, options, ...) {
.Last.value <<- x
if (!is.null(old_hook))
old_hook(x, options, ...)
else
knitr::knit_print(x, options, ...)
})
```
```{r mean diff}
5-mean(dnorm(40,5,2))/5
```
The value was `r .Last.value`.