Pre-work Digital fundamentals week 2

What is a Programming Language?

• Definition: Sets of instructions for computers to perform operations.

• Types of Programming Languages:

  • Machine Codes: Numeric codes (binary) that are processor-specific (e.g., op-code)- only computer understands

  • Assembly Codes: More human-friendly, symbolic representations (e.g., add r1,r2).

  • High-Level Programming Languages: Closer to human language; includes:

    • Examples: C, C++, Java, BASIC, FORTRAN.

    • Simpler syntax (e.g., uint8_t y = 10 + 23;).

  • MATLAB: A high-level scripting language similar to Python.

MATLAB User Interface

• Key Components:

  • Command Window: Where commands/codes are entered.-user selection

  • Workspace: Displays all variables and their details.

  • Current Folder: Displays files in the active directory.

  • Active Directory: Selected folder for MATLAB’s working environment.

  • Help: Access help files when needed.

  • Add-Ons: Tools for additional functionality.

• Script Files: More efficient way to write MATLAB code (create .m files).

MATLAB Script Files

• Assessment tasks use script files (.m files) for convenience.

• Variables: Named storage for data (one type per variable).

  • Types of variables:

    • Integer (whole numbers)

    • Floating-point (decimals)

    • Character/String (letters/symbols)

• Special Variable Types: Structs, tables, cell variables allow multiple data types.

Basic Numeric Variables in MATLAB

• To create variables, use the format: variableName = value;

• Defaults: Numeric variables are double-precision. Examples:

  • a = 1.5;

  • mass = 20;

    • lightVelocity = 2.99792e8;

      variables cannot contain spaces

    • semi colon stops the variables to being shown on the command window eg makes it cleaner

• Variable naming: Use meaningful names. Example of calculations:

  • force = mass * accel; (Newton's Law)

Basic Character Variables in MATLAB

• Creating character arrays:

  • Use single apostrophes, e.g., labelNorth = 'North';

• Convert numbers to strings using num2str():

  • Example:

    • MyNumStr = num2str(MyNum);

Using Mathematical Operators

• Basic operations in MATLAB:

  • Multiplication: * or for array of numbers .* to multiply against the whole array

  • Division: / for array ./

  • Addition: +

  • Subtraction: -

  • Powers: ^

• Follow BODMAS rules for order of operations.

• Example calculations:

  

  • x = (5 + 2)^2 - 2 * (7 + 3);

  • y = (25 - 5) / (6 * sqrt(9));

Debugging Tips and Tricks

• Recognize and correct errors in MATLAB code effectively.

• Error messages: Displayed in red, indicating the type and line of error.

• Warnings: Displayed in orange, suggesting potential issues without stopping execution.

Debugging in MATLAB

• Use breakpoints to halt execution at specific lines.

• MATLAB sections are indicated by the %% symbol and separate your script file into multiple, stand-alone parts that can be run as a whole (using Run) or individually (using Run Section). Sections are useful when you have MATLAB scripts containing short code samples that are not necessarily related to each other.

• Utilize Workspace to monitor variable states as you debug.

• Commenting Code:

  • Use % for single comments; %{ for block comments.

  • Essential for maintaining code clarity.

  • helps understanding fro whne coming back to the code

  • it easier to recall the purpose and functionality of specific code segments.

Importing Data into MATLAB

• MATLAB’s capability to import/export various file types.

• Import Wizard: For user-friendly data importing. Initiate through dragging files or using the Import Data button.

• Supported formats: Excel, text, binary, audio, images.

• To import files automatically using code, there are several in-built functions

  available that allow you to import the following file formats:

  • Delimited files (including spreadsheets, comma separated value files, etc.)

  • Audio files (including .wav, .ogg, .aiff, .aifc, .au, .flac, .opus, .mp3, and .m4a)

  • Image files (most image file formats, e.g., .jpeg, .png, .tiff, .bmp, .gif, etc…)

  • Binary data (e.g. text files)

Specific Import/Export Functions

• Delimited files:

  • readmatrix(): Imports numeric data.

  • readcell(): Imports both numbers and text as cell arrays.

• Audio files: Use audioread() and audiowrite() for importing and exporting audio data.

• Image files: Use imread() to import images and imwrite() to export them.

Conclusion

• The lecture provided an introduction to the MATLAB environment, basic variable creation, mathematical operations, debugging strategies, and file import/export functionalities.

• Emphasized the importance of using script files for tasks and maintaining clean, commented code for clarity and troubleshooting.

Lecture Overview

Title: Digital Fundamentals Introduction to the MATLAB Environment

Lecturer: Dr. Katrina Neville

Contents Covered:

• Navigating the MATLAB User Interface: Understanding the layout and functions of the various panels and windows in MATLAB.

• Creating and Manipulating Variables: Learning how to create variables, assign values, and perform operations with them.

• Debugging Techniques: Strategies for identifying errors in code and using the debugging tools in MATLAB effectively.

• Importing Various File Types into MATLAB: Understanding the capabilities of MATLAB to work with different data formats such as Excel spreadsheets, text files, images, and audio files.

• CRICOS Provider Number: 00122A | RTO Code: 3046

What is a Programming Language?

• Definition: A programming language is a system of notations used to write instructions for a computer to execute specific operations. It enables interaction between humans and machines by providing a means to communicate tasks.

• Types of Programming Languages:

  • Machine Codes: These are low-level codes directly executed by the computer's processor, consisting of binary numbers (0s and 1s) that are specific to each type of processor.

  • Assembly Codes: A more human-readable form of machine code, employing symbolic representations for operations (e.g., add r1,r2), making it somewhat easier to understand for developers.

  • High-Level Programming Languages: These languages are designed for ease of use and are closer to natural languages. Examples include:

    • C, C++, Java, BASIC, FORTRAN: Each of these languages has its own syntactical rules but generally allows for more human-friendly programming.

    • Example of Simplified Syntax: uint8_t y = 10 + 23;

• MATLAB: A high-level scripting language similar to Python, known for its simplicity and effectiveness in numerical computations.

MATLAB User Interface

• Key Components:

  • Command Window: The primary area where users can input commands and see immediate results from executed code.

  • Workspace: A window that provides a detailed view of all current variables and their attributes (values, sizes), assisting in tracking data management.

  • Current Folder: Displays the contents (files and folders) of the current working directory that MATLAB is accessing.

  • Active Directory: The selected folder utilized by MATLAB for reading and saving files.

  • Help: An integrated assistance tool offering documentation and tips to guide users in MATLAB usage.

  • Add-Ons: A feature that allows users to install additional tools and applications to enhance MATLAB's capabilities.

  • Script Files: Efficient for writing long amounts of MATLAB code as .m files, enabling easy execution and processes.

MATLAB Script Files

• Importance in Assessments: Assessment tasks often require the use of script files to streamline coding processes and provide organized code structure.

• Variables: Containers for storing data that can only hold a specific type of information.

• Types of Variables:

  • Integer: Whole numbers without fractions.

  • Floating-Point: Numbers that represent real numbers, allowing fractions (decimals).

  • Character/String: Data types that store letters, symbols, or strings of text.

  • Special Variable Types: Including structs, tables, and cell arrays, which enable the storage of different data types in a single variable.

Basic Numeric Variables in MATLAB

• Creating Variables: Utilizes the syntax: variableName = value;

• Default Data Types: Numeric variables are by default stored in double-precision format. Example initializations include:

  • a = 1.5;

  • mass = 20;

  • lightVelocity = 2.99792e8;

• Variable Naming Conventions: Naming should be descriptive, making it clear what the variable represents. Example of a physical calculation: force = mass * accel; representing Newton's Second Law of Motion.

Basic Character Variables in MATLAB

• Character Arrays: Defined with single quotation marks. For example, labelNorth = 'North';

• Converting Numbers to Strings: Use the function num2str() to transform numerical values into string format. Example conversion:

  • MyNumStr = num2str(MyNum);

Using Mathematical Operators

• Overview of Operations: Basic mathematical operations supported in MATLAB include:

  • Multiplication: *

  • Division: /

  • Addition: +

  • Subtraction: -

  • Exponentiation: ^

• Order of Operations: MATLAB follows PEMDAS/BODMAS rules for mathematical expressions, determining the sequence of operations. Example expressions:

  • x = (5 + 2)^2 - 2 * (7 + 3);

  • y = (25 - 5) / (6 * sqrt(9));

Debugging Tips and Tricks

• Error Handling: Recognizing and troubleshooting errors that may arise in the code is crucial. Error messages appear in red to indicate issues, while warnings appear in orange, alerting users to potential problems.

• Debugging Techniques in MATLAB:

  • Utilize breakpoints to pause execution at specific code lines and examine variables.

  • Leverage the Workspace to monitor variable states during debugging sessions.

  • Commenting Code: Employ comments to clarify code logic, using % for single-line comments and %{ %} for block comments, fostering better code management.

Importing Data into MATLAB

• Capability Overview: MATLAB supports the import/export of various data formats.

• Import Wizard: A user-friendly tool to facilitate the importing of data through dragging files or using the Import Data button.

• Supported Formats Include:

  • Excel, Text, Binary, Audio, Images: Each requiring specific functions for data manipulation.

  • Specific Import/Export Functions:

    • For delimited files: use readmatrix() to import numerical data, and readcell() to import mixed data types as cell arrays.

    • For audio files: functions such as audioread() and audiowrite() handle audio data inputs and outputs effectively.

    • For images: leverage imread() to import images and imwrite() for saving exported images.

Conclusion

• This lecture provided an extensive introduction to the MATLAB environment, focusing on the foundational aspects of variable creation, mathematical operations, debugging strategies, and file import/export functionalities.

• It emphasized the importance of using script files for efficient coding in MATLAB and the necessity of maintaining clean, well-commented code for clarity and troubleshooting.