Reputation:
I am going over my review worksheet and was looking for some help with finding the recurrence relation for chained matrix multiplication using dynamic programming.
The problem verbatim:
Consider the optimal parenthesization problem for the chained matrix product M0M1…Mn - 1
with associated dimension sequence (d0, d1, … ,dn)
. Derive the recurrence relation on which the dynamic programming solution for this problem is based, i.e., a recurrence relation for the minimum number mij of multiplications over all parenthesizations of the chained product MiM1…Mj
. Don’t forget the initial condition.
I understand the formula for M[i,j]
(M[i,j] = M[i,k] + M[k+1,j] + pqr)
. This definitely has recursion. But how to I determine the recurrence relation? Is this not the recurrence relation already? Also what is mean by "associated dimension space"?
Upvotes: 0
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Reputation: 6460
See section 6.5(Chain Matrix Multiplication) from http://www.cs.berkeley.edu/~vazirani/algorithms/chap6.pdf
Here by associated dimension he means that the dimension of each matrix i.e M0 has dimensions d0, M1 has d1, M2 has d2 .... so on.
Upvotes: 2