Matrix Power
Compute the k-th power of a matrix. Whereas x^k computes
element wise powers, x %^% k corresponds to k -
1 matrix multiplications, x %*% x %*% ... %*% x.
x %^% k
x |
a square |
k |
an integer, k >= 0. |
Argument k is coerced to integer using as.integer.
The algorithm uses O(log2(k)) matrix multiplications.
A matrix of the same dimension as x.
If you think you need x^k for k < 0, then consider
instead solve(x %^% (-k)).
Based on an R-help posting of Vicente Canto Casasola, and Vincent Goulet's C implementation in actuar.
%*% for matrix multiplication.
A <- cbind(1, 2 * diag(3)[,-1])
A
A %^% 2
stopifnot(identical(A, A %^% 1),
A %^% 2 == A %*% A)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.