Dynamic Reporting with R Markdown and Knitr

R Markdown, powered by the knitr engine, lets you combine narrative text, live R code, and its output into a single reproducible document — rendered as HTML, PDF, or Word with one click.

1. Installing R Markdown

install.packages("rmarkdown")
# For PDF output, you also need a LaTeX distribution:
install.packages("tinytex")
tinytex::install_tinytex()

2. Creating an R Markdown File

In RStudio: File → New File → R Markdown. This generates a .Rmd file with a YAML header, narrative text, and embedded "code chunks."

---
title: "Sales Analysis Report"
author: "Your Name"
date: "2026-07-18"
output: html_document
---

## Introduction

This report analyzes quarterly sales performance.

```{{r setup, include=FALSE}}
library(dplyr)
library(ggplot2)
sales <- read.csv("data/sales.csv")
```

## Summary Statistics

```{{r}}
summary(sales$revenue)
```

## Revenue Trend

```{{r, echo=FALSE}}
ggplot(sales, aes(x = month, y = revenue)) +
  geom_line() + theme_minimal()
```

3. Code Chunk Options

4. Rendering ("Knitting") the Document

Click the Knit button in RStudio, or run from the console:

rmarkdown::render("report.Rmd", output_format = "html_document")

5. Multiple Output Formats

---
output:
  html_document: default
  pdf_document: default
  word_document: default
---

With multiple formats listed, you can render each specifically:

rmarkdown::render("report.Rmd", output_format = "pdf_document")
rmarkdown::render("report.Rmd", output_format = "word_document")

6. Inline R Code

Embed live values directly inside sentences using backticks:

The average revenue this quarter was `r round(mean(sales$revenue), 2)` dollars,
across `r nrow(sales)` recorded transactions.

7. Tables with knitr::kable()

library(knitr)

kable(head(sales), caption = "Sample of Sales Data")

8. Why Reproducibility Matters

Because the report re-runs the actual R code every time it's knitted, your narrative, tables, and charts can never silently fall out of sync with your data — unlike a manually copy-pasted report.

9. Production-Ready Checklist

• ✅ Structure your .Rmd with a clear YAML header — title, author, date, output format.
• ✅ Use chunk options deliberately — echo, include, eval — to control what readers see.
• ✅ Use inline R code — for numbers that stay in sync with your data.
• ✅ Knit to multiple formats — HTML for interactivity, PDF/Word for sharing.