rmarkdown Parameters declaration and using parameters

Question

How to create parameters in Rmarkdown and use the parameters in script?

Answer 1

Create parameters using params attribute inside Rmarkdown script.

Example -

---
title: "Rmarkdown Parameters"
output: html_document
params:
  data: mpg
---

To use parameter in Rmarkdown script, go to knit and click on knit with parameters, then type the parameter value and press enter.

To use parameter inside r script, type the pramteer variable preceded with params$ to use it.

Such as `r params$data`

The parameter is applied in Rmarkdown script and then shows a html page.