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ECIV 301. Programming & Graphics Numerical Methods for Engineers Lecture 12 System of Linear Equations. Objectives. Introduction to Matrix Algebra Express System of Equations in Matrix Form Introduce Methods for Solving Systems of Equations Advantages and Disadvantages of each Method.
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ECIV 301 Programming & Graphics Numerical Methods for Engineers Lecture 12 System of Linear Equations
Objectives • Introduction to Matrix Algebra • Express System of Equations in Matrix Form • Introduce Methods for Solving Systems of Equations • Advantages and Disadvantages of each Method
Matrix Algebra Rectangular Array of Elements Represented by a single symbol [A]
Row 1 Row 3 Column m Column 2 Matrix Algebra n x m Matrix
3rd Row 2nd Column Matrix Algebra
Matrix Algebra 1 Row, m Columns Row Vector
Matrix Algebra n Rows, 1 Column Column Vector
Main Diagonal Matrix Algebra If n = m Square Matrix e.g. n=m=5
Matrix Algebra Special Types of Square Matrices Symmetric: aij = aji
Matrix Algebra Special Types of Square Matrices Diagonal: aij = 0, ij
Matrix Algebra Special Types of Square Matrices Identity: aii=1.0 aij = 0, ij
Matrix Algebra Special Types of Square Matrices Upper Triangular
Matrix Algebra Special Types of Square Matrices Lower Triangular
Matrix Algebra Special Types of Square Matrices Banded
Matrix Operating Rules - Equality [A]mxn=[B]pxq n=p m=q aij=bij
Matrix Operating Rules - Addition [C]mxn= [A]mxn+[B]pxq n=p cij = aij+bij m=q
Matrix Operating Rules - Addition Properties [A]+[B] = [B]+[A] [A]+([B]+[C]) = ([A]+[B])+[C]
m=p Matrix Multiplication [A] n x m . [B] p x q = [C] n x q
Matrix Multiplication Example
Matrix Multiplication - Properties If dimensions suitable Associative: [A]([B][C]) = ([A][B])[C] Distributive: [A]([B]+[C]) = [A][B]+[A] [C] Attention: [A][B] [B][A]
Operations - Inverse [A] [A]-1 [A] [A]-1=[I] If [A]-1 does not exist [A] is singular
Operations - Trace Square Matrix tr[A] = Saii
Homework Problems 9.1, 9.2, 9.3 Due Date: Oct 6