In over 25 years of MATLAB programming, I’ve contributed a few utilities and MATLAB gadgets that I’ve found helpful. For example:

- unplot Delete the most recently plotted object(s). Used it so, so many times.
- latex Convert a matrix into a LaTeX matrix or table. Maybe the table data type in MATLAB has obsoleted this, but it’s still handy for writing papers from time to time.
- gslope Click twice on a plot and get the slope between the points. Useful for determining convergence rates.
- sparse Toeplitz matrix construction Some practical sparse matrices are Toeplitz. This takes the pain out of constructing them.
- piecewise-defined function builder Creates a single callable function from a collection of piecewise definitions.