Matrix Chain
Multiplication
Contents:
Introduction to
Matrix Chain
Multiplication
Algorithm
Example
Conclusion
Introduction to Matrix Chain Multiplication
Matrix Chain Multiplication is a critical optimization
problem in computer science. Understanding the
efficiency of matrix operations can significantly
enhance performance in various applications,
including graphics processing and scientific
computing. We will delve into the algorithms that
solve this problem effectively.
The Matrix Chain Multiplication problem
involves determining the most efficient way to
multiply a given sequence of matrices. The goal
is to minimize the total number of scalar
multiplications required. This involves
understanding the associative property of matrix
multiplication and how to exploit it for
efficiency.
Algorithm
If i= j
m[i, j]  0
Else
m[i, j]  ∞
For k  i to j – 1
m[i, j] = m[i, k] + m[k+1, j] + Pi-1 Pk Pj
Example
 A = 4 × 5
B = 5 × 3
C = 3 × 2
D = 2 × 7
 P0 P1 P2 P3 P4
< 4 5 3 2 7 >
 m[1, 2] = m[1, 1] + m[2, 2] + P0P1P2 = 0 + 0 + 4 × 5 × 3 = 60
k[1, 1]
 m[2, 3] = m[2, 2] + m[3, 3] + P1P2P3 = 0 + 0 + 5 × 3 × 2 = 30
k[2, 2]
 m[3, 4] = m[3, 3] + m[4, 4] + P2P3P4 = 0 + 0 + 3 × 2 × 7 = 42
k[3, 3]
 m[1, 3] = m[1, 1] + m[2, 3] + P0P1P3 = 0 + 30 + 4 × 5 × 2 = 70 k[1]
m[1, 3] = m[1, 2] + m[3, 3] + P0P2P3 = 60 + 0 + 4 × 3 × 2 = 84
k[2]
 m[2, 4] = m[2, 2] + m[3, 4] + P1P2P4 = 0 + 42 + 5 × 3 × 7 = 147
k[2]
2
3
4 1
1
3
2
2 4
1
1
3
3
3
1
1
2
2
3
3
4
4
126
70 100
60 30 42
0 0 0 0
m S[k]
j j i
i
s[1, 4]k=3
[1, 3]k=1 [4, 4]
[1, 1] [2, 3]k=2
[3, 3]
[2, 2]
((A(BC))D)
Conclusion
In conclusion, optimizing computational efficiency
through Matrix Chain Multiplication is crucial for
enhancing performance in computational tasks.
Future work may involve exploring parallel processing
techniques and heuristic algorithms to further
improve efficiency in real-world applications
Thank You

Optimizing Matrix Chain Multiplication.pptx

  • 1.
  • 2.
  • 3.
    Introduction to MatrixChain Multiplication Matrix Chain Multiplication is a critical optimization problem in computer science. Understanding the efficiency of matrix operations can significantly enhance performance in various applications, including graphics processing and scientific computing. We will delve into the algorithms that solve this problem effectively.
  • 4.
    The Matrix ChainMultiplication problem involves determining the most efficient way to multiply a given sequence of matrices. The goal is to minimize the total number of scalar multiplications required. This involves understanding the associative property of matrix multiplication and how to exploit it for efficiency.
  • 5.
    Algorithm If i= j m[i,j]  0 Else m[i, j]  ∞ For k  i to j – 1 m[i, j] = m[i, k] + m[k+1, j] + Pi-1 Pk Pj
  • 6.
    Example  A =4 × 5 B = 5 × 3 C = 3 × 2 D = 2 × 7  P0 P1 P2 P3 P4 < 4 5 3 2 7 >
  • 7.
     m[1, 2]= m[1, 1] + m[2, 2] + P0P1P2 = 0 + 0 + 4 × 5 × 3 = 60 k[1, 1]  m[2, 3] = m[2, 2] + m[3, 3] + P1P2P3 = 0 + 0 + 5 × 3 × 2 = 30 k[2, 2]  m[3, 4] = m[3, 3] + m[4, 4] + P2P3P4 = 0 + 0 + 3 × 2 × 7 = 42 k[3, 3]  m[1, 3] = m[1, 1] + m[2, 3] + P0P1P3 = 0 + 30 + 4 × 5 × 2 = 70 k[1] m[1, 3] = m[1, 2] + m[3, 3] + P0P2P3 = 60 + 0 + 4 × 3 × 2 = 84 k[2]  m[2, 4] = m[2, 2] + m[3, 4] + P1P2P4 = 0 + 42 + 5 × 3 × 7 = 147 k[2]
  • 8.
    2 3 4 1 1 3 2 2 4 1 1 3 3 3 1 1 2 2 3 3 4 4 126 70100 60 30 42 0 0 0 0 m S[k] j j i i
  • 9.
    s[1, 4]k=3 [1, 3]k=1[4, 4] [1, 1] [2, 3]k=2 [3, 3] [2, 2] ((A(BC))D)
  • 10.
    Conclusion In conclusion, optimizingcomputational efficiency through Matrix Chain Multiplication is crucial for enhancing performance in computational tasks. Future work may involve exploring parallel processing techniques and heuristic algorithms to further improve efficiency in real-world applications
  • 11.

Editor's Notes

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