EE 153: Intro to MATLAB Environment

• The material is for EE 153: Introduction to MATLAB, taught by D. Kwegyir (PhD) of the Department of Electrical & Electronic Engineering, College of Engineering

Module 1: Introduction to MATLAB Environment

• Module 1 focuses on introducing the MATLAB environment.

Module 1.0: Learning Objectives

• Introduce the MATLAB interface
• Cover basic commands, variable definitions, and data types.
• Explain basic arithmetic operations.
• Provide practice with calculations and variable assignments.

Module 1.1: Introduction to MATLAB

• MATLAB stands for MATrix LABoratory.
• MATLAB combines computation and visualization for engineers
• MATLAB is an executive program and is made with a script.
• Primarily designed for matrix computations.
• The MATLAB environment allows users to manage variables, import/export data, perform calculations, generate plots, and develop/manage files.

Module 1.2: Parts of the MATLAB Window

• Command Window: where commands are entered at the command line (indicated by >>).
• Current Folder: used to view folders and access files.
• Workspace: used to view program variables; double-clicking a variable opens it in the Array Editor.

Module 1.3: MATLAB Syntax

• MATLAB is a high-level programming language and environment for numerical computation, visualization, and programming.
• MATLAB syntax includes variable declarations, vectors and matrices, functions and scripts, and control flow statements.

Module 1.3.1: Key Elements of MATLAB Syntax

• Commands: Executed line-by-line, e.g., disp('Hello, MATLAB!').
• Variables: Dynamically typed; no explicit type declaration needed, e.g., x = 10;.
• Operators: Arithmetic (+, -, *, /), relational (==, <, >), and logical (&&, ||).
• Functions: Predefined or user-defined reusable code blocks, e.g., y = sin(x);.

Module 1.4: Variables

• Variables are containers for data.
• MATLAB is generally case-sensitive.
• Valid variable names must begin with a letter and contain only letters, digits, and underscores, with no spaces or special characters.
• In MATLAB, every variable is an array or matrix, even if it holds a single (scalar) value.
• Variables can represent a number, an expression, or a data structure.
• MATLAB variables are dynamically typed.
• Variables must have values before use.
• Results not assigned to a variable are assigned to ans.
• Multiple assignments can be on the same line.
• If a variable exists, MATLAB replaces the content and allocates new storage if needed.
• Example command: x = 3; % Define variable x and initialize it with the value 3.

Module 1.5: Special Variables & Constants

• ans: Most recent answer.
• eps: Accuracy of floating-point precision.
• i, j: The imaginary unit √-1.
• Inf: Infinity.
• NaN: Undefined numerical result (not a number).
• pi: The number π.
• clc: Clears command window.
• clear: Removes all variable values from the workspace.
• disp: Displays values inside a variable/matrix.
• help: Displays help text inside the Command Window for a specified function, operator, symbol, method, class, or toolbox.
• who: Displays all the variable names used.
• iskeyword('while'): used to check if while is a reserved keyword.

Module 1.6: Examples on Variables

• Example code and their result:
  • str = 'Hello World!' results in str = Hello World!
  • n = 2345 results in n = 2345
  • d = double(n) results in d = 2345
  • un = uint32(789.50) results in un = 790
  • rn = 5678.92347 results in rn = 5678.9
  • c = int32 results in c = 5679

Module 1.7: Data Types in MATLAB

• By default, MATLAB stores all numeric variables as double-precision floating-point values.
• Data type categories in MATLAB include numeric types, characters and strings, cell arrays, and data type conversion.
• Common Data Types:
  • int8: 8-bit signed integer
  • uint8: 8-bit unsigned integer
  • single: single precision numerical data
  • double: double precision numerical data
  • logical: logical values of 1 or 0, representing true and false respectively
  • char: character data (strings are stored as a vector of characters)

Module 1.8: Commonly Used Operators and Special Characters

• +: Addition operator.
• -: Subtraction operator.
• *: Scalar and matrix multiplication.
• .*: Array multiplication.
• ^: Scalar and matrix exponentiation.
• .^: Array exponentiation.
• \: Left division.
• /: Right division.
• .\: Array left division.
• ./: Array right division.
• :: Colon; generates regularly spaced elements, represents entire rows/columns.
• (): Parentheses; encloses function arguments/array indices, overrides precedence.
• []: Brackets; encloses array elements.
• .: Decimal point.
• ...: Ellipsis; line-continuation operator.
• ,: Comma; separates statements/elements in a row.
• ;: Semicolon; separates columns, suppresses display.
• %: Percent sign; designates comments and specifies formatting.
• ': Quote sign and transpose operator.
• .': Non-conjugated transpose operator.
• =: Assignment operator.

Module 1.9: Operators

• Relational operators check relationships between numbers, returning TRUE or FALSE.
• Logical operators check if numbers fulfill conditions, returning TRUE or FALSE.

Module 1.9.1: Relational Operators

• Equal To: a == b
• Not Equal To: a ~= b
• Greater than: a > b
• Greater or equal to: a >= b
• Lesser than: a < b
• Lesser or equal to: a <= b

Module 1.9.2: Logical Operators

• Logical AND: a && b
• Logical OR: a || b
• Logical NOT: a ~ b

Module 1: Practice Problems

• Practice 1: Basic Operations with Scalars
  • Define scalar variables num1 (15) and num2 (8). Calculate and display the sum, difference, product, and division (to two decimal places).
• Practice 2: Combined Arithmetic Expression
  • Initial investment of $1000 (investment), annual interest rate of 5% (rate).
  • Calculate and display the simple interest investment value after 3 years: future value investment × (1 + rate × years)
• Practice 3: Operation Precedence
  • Given p = 12, q = 4, r = 3, evaluate result = p × q – (p+r)/r + 2q, being mindful of operation precedence.