Hiding selected lines in code chunk

[ugurcanb]

Hello, I'm new to RStudio. I'm trying to hide last line in the code chunk with indexing, but it's not working. Is there any way to hide the last line? echo = -5 doesn't work as well.

```{r, echo=1:4}
new_revenue_data %>%
  filter(Year >= 2018) %>%
  arrange(Year) %>%
  head() %>%
  knitr::kable()
```

[GreyMerchant]

Hi there!

You can have a look here: r - RMarkdown Chunk - Don't echo last expression - Stack Overflow

As you can see there are some ways to get around it but it won't work for all circumstances. Let me know if this helps/solves your problem

[ugurcanb]

Unfortunately it didn't work. I've tried few things to understand how echo works. It seems that echo doesn't work with the pipe operators

[GreyMerchant]

Hi there,

I performed a reprex with your problem and it works.

See screenshot:

See code:

---

title: "Hack the output with hooks"

knitr::opts_hooks$set(rm.last = function(options) {
  options$code <- 
    paste0(
      options$code, 
      c(rep("", length(options$code) - options$rm.last), 
        rep(" # REMOVE", options$rm.last)
      )
    )
  options
})

builtin_source_hook <- knitr::knit_hooks$get('source')

knitr::knit_hooks$set(source = function(x, options) {
  if (!is.null(options$rm.last))  
    x <- grep("# REMOVE$", x, invert = TRUE, value = TRUE)
  if (length(x) > 0) {
    return(builtin_source_hook(x, options))
  } else {
    invisible(NULL)
  }
})

a <- 1
b <- 2
x <- a + b
print(paste(c("`x` is equal to ", x), collapse=""))

library(tidyverse)

output <- 
  mtcars %>%
  filter(mpg >= 21) %>%
  arrange(mpg) %>%
  head() %>%
  knitr::kable()

output

As you will see we only have library(tidyverse) loading while the last 5 lines got disabled via rm.last=5.

[GreyMerchant]

It is tuff to paste the code without chunks etc vanishing. See full screenshot here for code:

[ugurcanb]

Thank you very much for your work, however I don't understand how rm.last works. Why all the output assignment have disappeared? I count the last 5 lines so i think it should output until the line with "mtcars".

[cderv]

If the aim is to print the the output of a chunk with kable without having to show kable in the source chunk, you can use the df_print method.

---
title: "test"
output: 
  html_document:
    df_print: kable
---

```{r}
library(dplyr)
```


```{r}
mtcars %>%
  filter(mpg >= 15) %>%
  arrange(cyl) %>%
  head()
```

echo = 1:4 will not work in your example because your are using the pipe %>%, and the all chain is accounted for 1 expression I think.