-*- mode: poly-markdown+r -*-
          ^^^^^^^^^^^^^^^------- local variable activates apropriate polymode
This demo shows you how to merge the source and output blocks in markdown
output. Note **knitr** puts R source and output in separate blocks by default.


```r
# first ``` are the end of previous source block; second ``` are the
of next output block
knit_hooks$set(chunk = function(x, options) {
    gsub("```\n+```", "", x)
})
```

See if it works:


```r
a = 1
a

## [1] 1
```


Source and output lived together happily ever in **knitr**.