MATLAB Matrix Manipulation and graphics

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MATLABMatrix Manipulation and graphics
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Matrix Generation in MATLAB
11 22 33 44 66 55 68 92 35 47 43 46 56 38 97 69
91 46 73 27
66 47 97 27
55 68 92 43 46 56 69 91 46
A
D
C
A 4 3 4 4 6 8 3 6 6 B 35 22 40 C
A(24,13) D A(,end) E A(2, ) F E
E2 G B D
E
55 68 92 35 47
68 59 37 24
66 47 97 27
G
55 68 92 35 47
F
57 70 94 37 49
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Colon Notation

• Starting Point Step Ending Point
• A 1 2 3 4 5 6 7
• A 17
• B 1 3 5 7 9 11 13
• B 1213
• C 10 9 8 7 6 5
• C 10 -1 5

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Common Matrices in MATLAB

• ones(3,4) All ones (3x4)
• zeros(2) All zeroes (2x2)
• eye(3) Identity (3x3)
• rand(4,5) Random numbers between 0
  and 1 (4x5)
• magic(4) Dührers matrix (4x4)

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Array and Matrix Operations

• A Transpose of Matrix A
• inv(A) Inverse of Matrix A
• det(A) Determinant of Matrix A
• eig(A) Eigenvalues of Matrix A
• A.A . denotes element by element (array)
  multiplication of A by B. Same approach can be
  used for element by element division and
  exponention.
• CAUTION To do a matrix multiplication AB, the
  number of columns in A must be equal to the
  number of rows in B
• To do an array multiplication both matrices must
  have the same number of rows AND columns

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Size of a Matrix or an Array
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Solution of Linear Equations
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Simple Plots

• Plot(x,y) plots x vs y
• Plot(x1,y1,x2,y2) Used to show multiple plots in
  the same figure.
• Subplot(rows,columns,number)
• Other useful commands
• Hold Grid
• Title( ) axis( , , , )
• Xlabel( ) ylabel( )
• Type Help plot for details