R: opts_chunk is not valid

Question

I am working on my first R record, which works very well, except for one problem. I would like to be the numbers that I output with

`r realbignumber` 

have commas as a separator and max 2 decimal points: 123 456 789.12

To achieve this, I added a snippet at the beginning of my document that contains ...

 ```{r setup} knitr::opts_chunk$set(echo = FALSE, warning=FALSE, cache = TRUE, message = FALSE) knitr::opts_chunk$set(inline = function(x){if(!is.numeric(x)){x}else{prettyNum(round(x,1), big.mark = ",")}}) options(scipen=999) ``` 

Suppressing scientific numbers works like a charm, so the piece is definitely fulfilled. However, formatting the built-in output of numbers does not work.

Any ideas why this could be? Do these settings usually not work with R laptops?

Edit:

The solution proposed here also does not affect the output number format.

Answer 1

Here is an example that illustrates two ways to print large quantities in an R Markdown document. Firstly, the code for using the prettyNum() function in the built-in part of R.

 Sample document where we test printing a large number. First set the number in an R chunk. ```{r initializeData} theNum <- 1234567891011.03 options(scipen=999,digits=16) ``` The R code we'll use to format the number is: `prettyNum(theNum,width=23,big.mark=",")`. Next, print the large number. `r prettyNum(theNum,width=23,big.mark=",")`. 

An alternative to using chunk options is as follows.

  Now, try an alternative using knitr chunks. ```{r prettyNumHook } knitr::knit_hooks$set(inline = function(x) { if(!is.numeric(x)){ x }else{ prettyNum(x, big.mark=",",width=23) } }) ``` Next, print the large number by simply referencing the number in an inline chunk as `theNum`: `r theNum`. 

When both pieces of code are embedded in the Rmd file and knit, the output is as follows, showing that both technologies give the same result.

Yours faithfully,

Len