[ https://issues.apache.org/jira/browse/MATH-435?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Mikkel Meyer Andersen reopened MATH-435: ---------------------------------------- FieldMatrix also has to have the (duplicate) power functionality. > Efficient matrix power > ---------------------- > > Key: MATH-435 > URL: https://issues.apache.org/jira/browse/MATH-435 > Project: Commons Math > Issue Type: Improvement > Reporter: Mikkel Meyer Andersen > Assignee: Mikkel Meyer Andersen > Fix For: 3.0 > > Attachments: MATH435-patch1 > > Original Estimate: 4m > Remaining Estimate: 4m > > 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. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira