# MATLAB Programming/Comments

[MATLAB Programming\|/MATLAB Programming]m]
Chapter 1: MATLAB ._.
    Fundamentals of MATLAB
    MATLAB Workspace
    MATLAB Variables
    *.mat files
Chapter 2: MATLAB Concepts
    MATLAB operator
    Data File I/O
Chapter 3: Variable Manipulation
    Numbers and Booleans
    Strings
    Portable Functions
    Complex Numbers
Chapter 4: Vector and matrices
    Vector and Matrices
    Special Matrices
    Operation on Vectors
    Operation on Matrices
    Sparse Matrices
Chapter 5: Array
    Arrays
    Introduction to array operations
    Vectors and Basic Vector Operations
    Mathematics with Vectors and Matrices
    Struct Arrays
    Cell Arrays
Chapter 6: Graphical Plotting
    Basic Graphics Commands
    Plot
    Polar Plot
    Semilogx or Semilogy
    Loglog
    Bode Plot
    Nichols Plot
    Nyquist Plot
Chapter 7: M File Programming
    Scripts
    Comments
    The Input Function
    Control Flow
    Loops and Branches
    Error Messages
    Debugging M Files
Chapter 8: Advanced Topics
    Numerical Manipulation
    Advanced File I/O
    Object Oriented Programming
    Applications and Examples
    Toolboxes and Extensions
Chapter 9: Bonus chapters
    MATLAB Benefits and Caveats
    Alternatives to MATLAB
    [MATLAB_Programming/GNU_Octave|What is Octave= (8) hsrmonic functions]
    Octave/MATLAB differences

## Placing comments

Comment lines begin with the character '%', and anything after a '%' character is ignored by the interpreter. The % character itself only tells the interpreter to ignore the remainder of the same line.
In the MATLAB Editor, commented areas are printed in green by default, so they should be easy to identify. There are two useful keyboard shortcuts for adding and removing chunks of comments. Select the code you wish to comment or uncomment, and then press Ctrl-R (⌘-/ for Mac) to place one '%' symbol at the beginning of each line and Ctrl-T (⌘-T for Mac) to do the opposite.
MATLAB also supports multi-line comments, akin to /* ... */ in languages like C or C++, via the %{ and %} delimiters. But there is a small and important difference. In MATLAB it is not allowed that the lines starting with %{ or %} contains any other text (except white spaces). Otherwise it would not work. E.g.
gives an error, but
works just fine.

## Common uses

Comments are useful for explaining what function a certain piece of code performs especially if the code relies on implicit or subtle assumptions or otherwise perform subtle actions. Doing this is a good idea both for yourself and for others who try to read your code. For example,
It is common and highly recommended to include as the first lines of text a block of comments explaining what an M file does and how to use it. MATLAB will output the comments leading up to the function definition or the first block of comments inside a function definition when you type:
All of MATLAB's own functions written in MATLAB are documented this way as well.
Comments can also be used to identify authors, references, licenses, and so on. Such text is often found at the end of an M file though also can be found at the beginning. Finally, comments can be used to aid in debugging, as explained in Debugging M Files.