Get the potency of a matrix for inversion speed-up
Usage
omxGetRAMDepth(A, maxdepth = nrow(A) - 1)
Arguments
A
MxMatrix object
maxdepth
Numeric. maximum depth to check
Details
This function is used internally by the mxExpectationRAM function
to determine how far to expand $(I-A)^{-1} = I + A + A^2 + A^3 + ...$. It is
similarly used by mxExpectationLISREL in expanding $(I-B)^{-1} = I + B + B^2 + B^3 + ...$.
In many situations $A^2$ is a zero matrix (nilpotent of order 2). So when $A$ has large
dimension it is much faster to compute $I+A$ than $(I-A)^{-1}$.