A linear algebra program for the TI-84 Plus CE graphing calculator. Matrix automates the mechanical parts of linear algebra, such as computing determinants, row reductions, inverses, Cramer's rule, and more, while showing every step so you can follow along
Steps are rendered as typeset LaTeX directly, powered by the bundled libtexce rendering engine
Linear algebra courses require you to work through lengthy and repetitive calculations by hand. Matrix does the calculations for you and shows you its steps:
- Enter integer matrices up to 6x6 using a familiar spreadsheet style editor
- Pick an operation from a menu and get the result instantly
- Tap a key to page through step by step LaTeX explanations of the entire computation
- Exact rational arithmetic results are displayed as fractions
- Runs natively on your TI-84+ CE
| Operation | Description |
|---|---|
| Add / Subtract | Element-wise matrix addition and subtraction |
| Multiply | Full matrix multiplication with dot-product steps |
| Transpose | Transpose of any matrix |
| Determinant | Cofactor expansion with smart row/column selection |
| Inverse | Gauss-Jordan elimination on the augmented matrix [A | I] |
| REF / RREF | Row Echelon Form and Reduced Row Echelon Form |
| Cramer's Rule | Solve Ax = b with per-Δ step breakdowns |
| Minor / Cofactor | Compute M_{ij} and C_{ij} for any element |
| Minor Matrix | Full matrix of minors |
| Operation | Description |
|---|---|
| Dot Product | Scalar dot product of two vectors |
| Cross Product | 3D cross product |
| Projection | Orthogonal projection of u onto v plus the orthogonal complement |
| Operation | Description |
|---|---|
| Column Space Basis | Basis for Col(A) via pivot columns |
| Row Space Basis | Basis for Row(A) via non zero rows of RREF |
| Null Space Basis | Basis for Null(A) from free variables |
| Left Null Space Basis | Basis for Null(Aᵀ) |
| Span Test | Test whether a vector is in the span of a set or R^m |
| Independence Test | Test whether a set of vectors is linearly independent |
| Solve via RREF | Solve a linear system using row reduction |
Every operation generates a detailed explanation:
- Navigate forward and backward through steps with the left/right arrow keys
- Each step shows a plain text caption (e.g.,
R_2 ← R_2 − 2R_2) and a LaTeX rendered matrix or expression - For multi part operations like Cramers rule, a sub menu lets you inspect each individual Δ_i determinant
- A TI-84 Plus CE or TI-84 Plus CE Python Edition
- A USB cable and software to transfer files to the calculator Ti connect CE for windows and webtilp for MacOS/Linux/Chromebooks
- Download the latest MATRIX.8xp from the Releases page
- Connect your calculator to your computer via USB
- Get clibs from https://tiny.cc/clibs
- If you are on an OS above version 5.4, you need arTIfiCE to launch the program (this is likely the case)
- Open TI Connect CE or webtilp and send
MATRIX.8xpto your calculator, the fonts, and clibs and arTIfiCE (make sure to choose ARCHIVE when prompted)
- From the main menu, select Matrices -> Edit A
- Set the dimensions (e.g., 3x3) using the arrow keys then press [enter]
- Navigate to each cell with the arrow keys, press [enter] to type a value and confirm with [enter]
- Press [clear] to finish editing, then go to Operations -> Determinant
- Select slot A. the determinant is computed and displayed
- Press a key to view the step by step cofactor expansion, rendered in LaTeX
- Use left/right arrows to page through steps; [clear] to go back
| Key | Action |
|---|---|
| UP / DOWN | Scroll through menus and matrix rows |
| LEFT / RIGHT | Navigate matrix columns; page through steps |
| [enter] | Select a menu item, confirm input, or edit a cell |
| [clear] | Go back one screen |
| [del] | Set the current cell to 0 (in the editor) |
| [2nd] | Finish editing a matrix |
- Dimensions are set with an arrow key selector (1-6 for both rows and columns)
- The grid editor shows all cells at once
- Cell values are entered in a footer input line (supports multi digit numbers and negative signs)
- Resizing a matrix clears its contents
- Steps are rendered one at a time using LaTeX. each page shows a caption and a typeset formula or matrix
- The step counter (e.g.,
3/7) tells you where you are - For complex operations (Cramer's rule), a sub menu lets you view each sub computation
See CONTRIBUTING.md for the technical overview, project structure, build instructions, and testing.