This uses simulations to match the rse
dfWishart(omega, n, rse, upper, totN = 1000, diag = TRUE, seed = 1234)
omega
: represents the matrix for simulationn
: This represents the number of subjects/samples this comes from (used to calculate rse). When present it assumes the rse= sqrt(2)/sqrt(n)rse
: This is the rse that we try to match, if not specified, it is derived from n
upper
: The upper boundary for root finding in terms of degrees of freedom. If not specified, it is n*200totN
: This represents the total number of simulated inverse wishart deviatesdiag
: When TRUE
, represents the rse to match is the diagonals, otherwise it is the total matrix.seed
: to make the simulation reproducible, this represents the seed that is used for simulating the inverse Wishart distributionoutput from uniroot()
to find the right estimate
dfWishart(lotri::lotri(a+b~c(1, 0.5, 1)), 100)
Matthew L. Fidler
Useful links