README.md

In zachary-foster/glossary:

Glossary

This is an R package to add a glossary to an Rmarkdown-based website and facilitate linking terms to it. Glossary terms are defined in an Rmd file not rendered on the website. This file is rendered by the package into HTML and the <div>s containing glossary terms are extracted and modified to contain targets for HTML anchors. An example of a definition file is included in the pacakge and can be viewed here.

library(glossary)
glossary_def_path <- system.file(package = "glossary", "extdata/example_definitions.Rmd")
gloss <- glossary(definitions_path = glossary_def_path) # returns an R6 class

If the glossary is to be on the same page as the terms, then only the path to the term definition Rmd is needed, otherwise the glossary_path option must be used to specify the path to the Rmd file that will render the glossary. In this example, we will render the glossary terms on this page, so the glossary_path option was not used.

To link a term, use the add function of the glossary object in an inline R chunk. For example, writing:

We used the amazing `r gloss$add("glossary")` `r gloss$add("r package")` to make our glossary! Too bad its not on `r gloss$add("The Comprehensive R Archive Network (CRAN)", shown = "CRAN")` yet.

Would render to:

We used the amazing glossary r package to make our glossary! Too bad its not on CRAN yet.

The terms are case-insensitive and the shown option can be used to change what text is used to link to the term.

The gloss$render_all() function can then be used to render the glossary and the links from the terms used in the text to the rendered glossary definitions:

Example glossary

gloss$render_all()

Class

A class is a defined set of variables along with a set of functions designed to work with those variable. The specifics of how classes are structured vary greatly between programming languages, but the concepts are similar. For example, you might have a class called “Dog” that contained the dogs age (number), the dogs breed (text), and the name of the dogs owner (text). With those variables, the “Dog” class might have functions that make the dog a year older or change the owner of the dog, etc.

Function

Any command or operation the does something in a programming language is a function. Functions often have inputs that influence what the output is, but some don’t have inputs. Functions will usually return some type of output, but they might not, or they might have an effect besides what they return (this is rare in R, but common in other programming languages). The concept of functions, like variables, comes from math. For example, the equation for a line is y = mx + b. In R, you could make a function to return y given the values of m, x, and b, like so:

line <- function(m, x, b) {
  return(m * x + b)
}

And find the value for y, for a given set of inputs like so:

line(m = 2.5, x = 3, b = -1)
#> [1] 6.5

Glossary

An R package to add a glossary to an Rmarkdown-based website and facilitate linking terms to it.

Object

An instance of a class. In other words, a data with a defined type and functions designed to operate on it. For example, if you had a class for “Dog”, you might have an object of that class stored in a variable called “fido” and another called “scraps”.

R package

An R package is a set of user-defined functions organized so that people can easily share and use them. Most of the functions used by most R users are from R packages rather than those supplied by base R. R packages can be installed in a few ways, but the most common is to download them from The Comprehensive R Archive Network (CRAN) using the install.packages function. For example stringr is an R package that supplies functions to work with text.

install.packages("stringr")

Once installed, a package must be “loaded” using the library function before any functions it supplies can be used:

library("stringr")

The Comprehensive R Archive Network (CRAN)

A volunteer-run organization that hosts R packages and enforces standards for how they should be structured. When you install an R package using install.packages, you are installing from CRAN. CRAN is one of the major reasons R packages are so easy to install.

Variable

In programming, a variable is a name associated with a value that can change or “vary”. This is similar to how the word is used in math. For example, the equation for a line is y = mx + b. In this equation, all of the letters are variables that can represent any number.

zachary-foster/glossary documentation built on May 23, 2019, 7:04 p.m.