R markdown: Accessing variable from code chunk (variable scope) [duplicate]

Answer 1

You can acces to variable previously created so

`r variable`

But if the variable is numeric and you want add to a pdf document, you should convert variable in string so

`r toString(variable)`

Answer 2

Yes. You can simply call any previously evaluated variable inline.

e.g. If you had previously created a data.frame in a chunk with df <- data.frame(x=1:10)

`r max(df$x)`

Should produce

10

Answer 3

I would like to add that this is not the case for other languages than R. I know the question is solved and about R, but maybe someone else finds this useful:

Except engine='R' (default), all chunks are executed in separate sessions, so the variables cannot be directly shared. If we want to make use of objects created in previous chunks, we usually have to write them to files (as side effects). For the bash engine, we can use Sys.setenv() to export variables from R to bash (example). Another approach is to use the (experimental) runr package.

Source

Example in R:

x = 4

print(x)

## [1] 4

Python Example 2a):

x=1
print(x)

## 1

Python Example 2b):

print(x)

## Traceback (most recent call last):
##   File "<string>", line 1, in <module>
## NameError: name 'x' is not defined

Just FYI.