What is knitr?

knitr is an R package that lets you weave together written text and data analysis code into a single document, so your reports, papers, and presentations update automatically whenever your data changes. Instead of running your analysis, copying the results, and pasting them into a report, you write everything in one file and the tool generates a polished final document with your narrative, code, and results embedded together. At its core, the tool takes a source file containing both prose and R code, runs the code, and produces an output file with the results inserted in place. You can control how each piece of code behaves through simple options, such as specifying the image format for plots or how numbers should be rounded, without writing extra code to handle those details. It aims to guess sensible defaults so you can produce a report with minimal setup. The tool is designed for analysts, researchers, and data scientists who work in R and want to create reproducible reports. For example, a data scientist who runs a weekly analysis could use it to generate a consistent report each week without manually re-copying numbers. An academic researcher could use it to ensure a paper's figures and tables always match the underlying data and code. The project was built to address practical frustrations with older tools that did similar work. The author wanted finer control over output formatting, such as setting individual plot widths or choosing image formats, without relying on workarounds or modifying core system files. The design gives users direct access to each step of the document generation process so they can customize the output without hacking the underlying engine.