David J. Krus Presents
David J. Krus Presents
David J. Krus Presents
Krus
presents
Matrix Algebra
for Social Sciences
Introduction to
Matrix Algebra
Dimensions of a Matrix
Number of Rows: 2
Number of Columns:3
A 2 x 3 Matrix
Elements of a Matrix
Principal Diagonal
Elements
Off-Diagonal Elements
Nomenclature of
Matrices
Rectangular
Square
Symmetric
Skew
Symmetric
Transpose
Triangulation
Matrix Algebra
Operations
on Matrix Elements
Addition of Matrix
Elements
on Matrices
Addition of Matrices
1+1=2
1+2=3
1+3=4
Major Addition of
Matrices
2+1=3
2+2=4
2+3=5
Major Addition of
Matrices
3+1=4
3+2=5
3+3=6
Minor Addition of
Matrices
1-1=0
1 - 2 = -1
1 - 3 = -2
Major Subtraction of
Matrices
2-1=1
2-2=0
2 - 3 = -1
Major Subtraction of
Matrices
3-1=2
3-2=1
3-3=0
Multiplication of
Matrices
(3*7) + (4*10) = 61
(3*8) + (4*11) = 68
(3*9) + (4*12) = 75
Multiplication of
Matrices
(5*7) + (6*10) = 95
(5*8) + (6*11) = 106
(5*9) + (6*12) = 117
Matrix Inversion
Matrix Inversion
Matrix Inversion
Powers of Matrices
Powers of Matrices
In Summation Notation
Summation Notation
X
MX
n
Algebraic Mean
1' X
Mx
n
Matrix Multiplication
1
2
1 1 1 1 1 3
4
5 15
Mx 3
5 5
Mean
1
2
1 1 1 1 1 3
4
5 15
Mx 3
5 5
True Variance
In Summation Notation
Summation Notation
nX (X )
2 2
2
x 2
n
True Variance
1' ( X X ' ) 1( 2)
x
2
2
n
Matrix Subtraction: X – X’
( 2)
1 1
1
2
1 1 1 1 1 3 1 2 3 4 5 1
4 1
1
5
x
2
52
Resulting Pairwise Differences
( 2)
0 1 2 3 4 1
1 0 1 2 3 1
1 1 1 1 1 2 1 0 1 2 1
3 2 1 0 1 1
4 3 2 1 0 1
x2 2
5
Triangulate the Matrix
( 2)
0 0 0 0 0 1
1
0 0 0 0 1
1 1 1 1 1 2 1 0 0 0 1
3 2 1 0 0 1
4 3 2 1 0 1
x
2
52
Square the Matrix Elements
0 0 0 0 0 1
1 0
0 0 0 1
1 1 1 1 1 4 1 0 0 0 1
9 4 1 0 0 1
16 9 4 1 0 1
x
2
25
Variance
Sum the
50 squared
Relational 2
2 elements
x
25
space
Covariance
In Summation Notation
Summation Notation
xy
cov xy
n
Covariance
D D
C
n
Obtained Scores
2 1
1 2
X 5 3
4 4
3 5
Deviation Scores
x y
1 2
2 1
D 2 0
1 1
0 2
Matrix Multiplication
D D
C
n
Matrix Multiplication
1 2
2 1
1 2 2 1 0
2 1 0 1 1 2 0
1 1 10 5
0 2 5 10
C 2 1
1 2
5 5
Diagonal Elements:
Sums of Squares
1 2
2 1
1 2 2 1 0
2 1 0 1 1 2 0
x’x 5
1 1 10
0 2 5 y’y
10 2 1
C
5 5 1 2
Off-Diagonal Elements:
Cross-Products
1 2
2 1
1 2 2 1 0
2 1 0 1 1 2 0
1 1 10 5
xy
0 2 yx
5 10 2 1
C
5 5 1 2
Variance-Covariance Matrix
1 2
2 1
1 2 2 1 0
2 1 0 1 1 2 0
1 1 10 5
0 2 5 10 2 1
C
5 5 1 2
Correlation
In Summation Notation
Summation Notation
z x z y
rxy
n
Correlation
Z Z
R
n
Obtained Scores
2 1
1 2
X 5 3
4 4
3 5
Standard Scores
Zx Zy
.71 1.41
1.41 .71
Z 1.41 .00
.71 .71
.00 1.41
Matrix Multiplication: Z’Z
.71 141
.
141
. .71
.71 141
. 141
. .71 .00
141 141
. .00
. .71 .00 .71 141
.
.71 .71
.00 .
141
R
5
Resulting Matrix
ZxZx
5.0 2.5
ZxZy
ZyZx
2.5 5.0
R ZyZy
5
Correlation Matrix
100
. .50
R
.50 100
.