Programming with MATLAB: Key Points

Working With Variables

Variables store data for future use. Their names must start with a letter, and can have underscores and numbers.
We can add, substract, multiply, divide and potentiate numbers.
We can also compare variables with <, >, ==, >=, <=, ~=, and use ~ to negate the result.
Combine logical operations with && (and) and || (or).
MATLAB stores data in arrays. The data in an array has to be of the same type.
You can supress output with ;, and print a variable with disp.
Use clear to delete variables, and clc to clear the console.

Some functions to initialize matrices include zeros, ones, and rand. They all produce a square matrix if only one argument is given, but you can specify the dimensions you want separated by a comma, as in zeros(rows,columns).
To select data points we use round brackets and provide the row and column indices of the elements we want. They can be just numbers or arrays of numbers, e.g. M(5,[3,4,5]).
Use the colon operator : to generate ordered arrays as start:end or start:increment:end.
Use the keyword end to obtain the index of the final element.
The colon operator by itself : selects all the elements.

Use readmatrix to read tabular CSV data into a program.
Use mean, min, max, and std on vectors to get the mean, minimum, maximum and standard deviation.
Use mean(array,DIM) to specify the dimension of your array in which to compute the mean.
For min, max, and std, the arguments need to be (array,[],DIM) instead.

Use plot(vector) to visualize data in the y axis with an index number in the x axis.
Use plot(X,Y) to specify values in both axes.
Document your plots with title("My title"), xlabel("My horizontal label") and ylabel("My vertical label").
Use hold on and hold off to plot multiple lines at the same time.
Use legend and add ,DisplayName="legend name here" inside the plot function to add a legend.
Use tiledlayout(m,n) to create a grid of m x n plots, and use nexttile to change the position of the next plot.
Choose the location and size of the tile by passing arguments to nextile as nexttile(position,[m,n]).
Use heatmap or imagesc to plot a whole matrix with values coded as color hues.

Save MATLAB code in files with a .m suffix.
The set of commands in a script get executed by calling the script by its name, and all variables are saved to the workspace. Be careful, this potentially replaces variables.
Comment your code to make it easier to understand using % at the start of a line.
The first line of any script or function (known as the H1 line) should be a comment. It typically includes the name of the program, and a brief description.
You can use help script_name to get the information in the H1 line.
Create new figures with figure, or new ‘invisible’ figures with figure(visible=‘off’). Remember to close them with close(), or close all.
Save figures with saveas(fig,"results/my_plot_name.png"), where fig is the figure you want to save, and can be replaced with gcf if you want to save the current figure.

Use conditional statements to make choices based on values in your program.
A conditional statement block starts with an if and finishes with end. It can also include an else.
Use elseif to nest conditional statements.
Use && (and), || (or) to combine logical operations.
Only one of the statement bodies is ever executed.

A MATLAB function must be saved in a text file with a .m extension. The name of the file must be the same as the name of the function defined in the file.
Define functions using the function keyword to start the definition, and close the definition with the keyword end.
Functions have an independent workspace. Access variables from your workspace inside a function by passing them as inputs. Access variables from the function returning them as outputs.
The header of a function with inputs an outputs has the form:

function [output_1,output_2,...] = function_name(input_1,input_2,...)