Details
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Improvement
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Status: Closed
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Major
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Resolution: Fixed
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None
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Description
For symmetric matrices A it is easy to find A^n also for large n by making an eigenvalue/-vector decomposition.
In general, if the structure of the matrix is not know and the n'th power is needed, A*A*...*A is way too inefficient. By using a binary representation and powers of 2, powers can be found far faster similar to finding 5^14 as 5^14 = 5^8 * 5^4 = ((5^2)^2)^2 * (5^2)^2 = x3 * x2 where x1 = 5^2, x2 = x1^2, and x3 = x2^2, thus saving a lot of computations.