Matlab in Emacs

Why programming and debugging Matlab in Emacs? There are two main reasons:

There are no Emacs emulators/keybindings available in Matlab on macOS, which makes Matlab programming less efficient.
One might need to program and debug Matlab scripts remotely.

Introduction

In order to program Matlab in Emacs, it must be able to

edit, including basic syntax, warning and error highlight, basic code completion, and
debug, including running and debugging the scripts and basic command completion.

These features are supported by the MATLAB mode for Emacs, which provides the matlab-mode, matlab-shell and mlint-mode.

Setup

Intall matlab-mode in Emacs,
- either from Melpa using package manager, or
- clone the repo to a local directory and load it manually in the init.el.

Add the following snippet into the init.el

;; associate .m file with the matlab-mode (major mode)
(add-to-list 'auto-mode-alist '("\\.m$" . matlab-mode))

;; setup matlab-shell
(setq matlab-shell-command "/Applications/MATLAB_R2021a.app/bin/matlab")
(setq matlab-shell-command-switches (list "-nodesktop"))

Usage

Editing

Open a .m file,
- It should be in matlab-mode with syntax highlights
- The mlint-minor-mode should be associated with matlab-mode and be turned on by default, with warning/error highlights
C-M-i to complete symbol (call the function matlab-complete-symbol)
C-M-a and C-M-e to jump to the beginning and end of a function ()
Jump to the line with warning/error highlights and M-x mlint-show-warning to display the warning/error.
M-x matlab-shell-describe-command (C-h RET f): open the help of a command
M-x matlab-shell-locate-fcn (C-c .): open the corresponding file of the function

Matlab-shell

M-x matlab-shell to open the matlab shell, use it the same as the Command Window in a Matlab application.
To run commands/scripts, one needs to go to the end of buffer M->, to the >>, and type the command/script name to run it.
Press <up> will run the command matlab-shell-previous-matching-input-from-input, and shows previous run commands.
TAB to complete commands
Variable related commands
- workspace to open the workspace browser
- who to list all variables in workspace
- open <varName> or openvar <varName to open a variable in the variable editor

Running and Debugging Scripts

Evaluate Section run the commands M-x matlab-shell-run-cell (C-M-return)
Evaluate Selection select lines and run the commands M-x matlab-shell-run-region (C-c C-r)
matlab-emacs use GUD (Grand Unified Debugger library) to support for debugging
- C-x C-a C-b (gud-break()) to set breakpoints
- C-x C-a C-v (gud-list-breakpoints()) to list all breakpoints
- C-x C-a C-x (gud-remove()) to remove breakpoints
When the program is running, the script (.m file) will enter matlab-shell-gud-minor-mode, and becomes read-only. Use the following commands for debugging
- h, open help
- b add breakpoint, same as C-x C-a C-b
- x remove breakpoint, same as C-x C-a C-x
- v list breakpoints, same as C-x C-a C-v
- s step, same as running dbstep in in the matlab shell
- n next, same as running dbstep in the matlab shell
- f finish function, same as running dbstep out in the matlab shell
- c continue, same as running dbcont in the matlab shell
- q quit, same as running dbquit in the matlab shell
gut-list-breakpoints will open a buffer under mlg-breakpoint-mode listing all breakpoints

Possible Problems

The mlint doesn't show warnings/errors highlights
- M-: matlab-toggle-show-mlint-warnings to toggle it on, or
- add (setq matlab-show-mlint-warnings t) to the init.el

Error: no MLint program available when trying to toggle on the matlab-toggle-show-mlint-warnings

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;; setup mlint for warnings and errors highlighting
(add-to-list 'mlint-programs "/Applications/MATLAB_R2021a.app/bin/maci64/mlint") ;; add mlint program for macOS
(add-to-list 'mlint-programs "/usr/local/MATLAB/R2021a/bin/glnxa64/mlint") ;; add mlint program for Linux