Transcription of Lecture 12: Chain Matrix Multiplication
{{id}} {{{paragraph}}}
Lecture12 Recallingmatrix Multiplication . Thechainmatrix multiplicationproblem. A dynamicprogrammingalgorithmforchainma-tr ix :An Matrix isa two-dimensionalarray ! " # # $ # ! " $ # .. % " & ! " ')(((* whichhas rowsand :Thefollowingis a+ , Matrix : - . ,1 ,,1/ !.! '(((*52 RecallingMatrixMultiplicationTheproduct of a Matrix anda Matrix is a Matrix givenby for and .Example:If ./01! ,,1'(* .01,,'(* then 43 43 ++.003 433')(*53 RemarksonMatrixMultiplication If is defined, maynotbedefined. Quitepossible that . Multiplicationis recursivelydefinedby 5 Matrix multiplicationisassociative, , Givena Matrix anda Matrix , thedirectway of multiplying is to computeeach for and .ComplexityofDirectMatrixmultiplication: Notethat has entriesandeachentry takes timetocomputesothetotalproceduretakes Givena Matrix , a Matrix anda Matrix , then canbecomputedintwo ways and :Thenumberof multiplicationsneededare: 5 When ,, +, 1and , then .3 ..5A bigdifference!Implication:Themultiplicat ion sequence (parenthesization)is important!)))))))
Recalling Matrix Multiplication The product of a matrix and a matrix is a matrix given by for and . Example: If 0 . / 1! , 1 ' (* then . 43
Domain:
Source:
Link to this page:
Please notify us if you found a problem with this document:
{{id}} {{{paragraph}}}