BJfindL2: Find the Wilks Confidence Interval Lower Bound for Betafun from the 2 dimensional Buckley-James Empirical Likelihood Ratio Function
Description
This function uses simple search to find the lower level (default 95%) 1 parameter Wilks confidence limits based on the Buckley-James empirical likelihood test function for two dimensional beta's. Betafun determines which 1 parameter we are finding the lower bound.
a 2-d vector: the NPMLEs: beta1 hat and beta2 hat.
ConfInt
a vector of length 2. Approx. length of the 2 conf. intervals for beta1 and beta2.
LLRfn
a function that returns -2LLR value.
Betafun
a function that takes the input of 2 parameter values (beta1,beta2) and
returns a parameter that we wish to find the confidence Interval lower Value.
dataMat
matrix of covariates
level
confidence level. Use chi-square(df=1), but calibration possible.
Value
A list with the following components:
Lowerthe lower confidence bound.
minParameterNloglikFinal values of the 2 parameters, and the log likelihood.
Details
Basically we repeatedly testing the value of the 2 parameters, finding the -2LLR values, until we find those Betafun
which the -2 log likelihood Ratio value is equal to 3.84 (or other level, if set differently).
References
Zhou, M. and Li, G. (2006).
Computing censored empirical likelihood ratio
by EM algorithm.
JCGS