ryan-heslin / matador

Package for plotting and working with matrices and vectors.

matador

matador is a simple package intended for plotting and working with matrices. It is intended to help students complete typical linear algebra problems using Rmarkdown.

Installation

matador depends on several of the core tidyverse packages, namely purrr, dplyr, and ggplot2, as well as the ggplot2 extension cowplot.

You can install matador using

devtools::install_github("ryan-heslin/matador")

Examples

Here are a few demonstrations of matador’s functionality:

matador makes it easy to visualize two-dimensional linear transformations:

library(matador)
#> Loading required package: magrittr
ggplot2::theme_set(ggplot2::theme_minimal())
plot_transform(trans = matrix(c(-1, 1,1, -1), nrow =2))

You can do the same for systems of equations:

plot_lines(m = matrix(c(-5, 2, 3, 7), nrow =2))

Or easily compute arbitrary powers of matrices:

mat_pows(matrix(1:9, nrow = 3), 1:5)
#> $`1`
#>      [,1] [,2] [,3]
#> [1,]    1    4    7
#> [2,]    2    5    8
#> [3,]    3    6    9
#> 
#> $`2`
#>      [,1] [,2] [,3]
#> [1,]   30   66  102
#> [2,]   36   81  126
#> [3,]   42   96  150
#> 
#> $`3`
#>      [,1] [,2] [,3]
#> [1,]  468 1062 1656
#> [2,]  576 1305 2034
#> [3,]  684 1548 2412
#> 
#> $`4`
#>       [,1]  [,2]  [,3]
#> [1,]  7560 17118 26676
#> [2,]  9288 21033 32778
#> [3,] 11016 24948 38880
#> 
#> $`5`
#>        [,1]   [,2]   [,3]
#> [1,] 121824 275886 429948
#> [2,] 149688 338985 528282
#> [3,] 177552 402084 626616

Or even display the orthogonal decomposition of a matrix:

plot_decomposition(square(1, 2, 1, -4))

For more details, take a look at the package vignette.

Acknowledgments

This package could not have been developed without the invaluable devtools package, which simplifies and automates the process of package development.

make_axes benefited greatly from this StackOverflow exchange.

Documentation for vec_helpers drew on this resource.

print_eqn was inspired by this StackOverflow post.

My primary linear algebra resource was Otto Bretscher’s Linear Algebra with Applications (5th ed.).

Professor Joshua Lansky’s linear algebra course inspired this package and gave me the knowledge in linear algebra to complete it.