gdfa_constant: Gamma Discriminant Function Approach for Estimating Odds...

Description Usage Arguments Value References

Description

See gdfa.

Usage

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gdfa_constant(y, xtilde, c = NULL, merror = FALSE,
  integrate_tol = 1e-08, integrate_tol_hessian = integrate_tol,
  estimate_var = TRUE, fix_posdef = TRUE, ...)

Arguments

y

Numeric vector of Y values.

xtilde

Numeric vector (or list of numeric vectors, if there are replicates) of Xtilde values.

c

Numeric matrix with C values (if any), with one row for each subject. Can be a vector if there is only 1 covariate.

merror

Logical value for whether there is measurement error.

integrate_tol

Numeric value specifying the tol input to hcubature.

integrate_tol_hessian

Same as integrate_tol, but for use when estimating the Hessian matrix only. Sometimes more precise integration (i.e. smaller tolerance) helps prevent cases where the inverse Hessian is not positive definite.

estimate_var

Logical value for whether to return variance-covariance matrix for parameter estimates.

fix_posdef

Logical value for whether to repeatedly reduce integrate_tol_hessian by factor of 5 and re-estimate Hessian to try to avoid non-positive definite variance-covariance matrix.

...

Additional arguments to pass to nlminb.

Value

List containing:

  1. Numeric vector of parameter estimates.

  2. Variance-covariance matrix.

  3. Returned nlminb object from maximizing the log-likelihood function.

  4. Akaike information criterion (AIC).

References

Whitcomb, B.W., Perkins, N.J., Zhang, Z., Ye, A., and Lyles, R. H. (2012) "Assessment of skewed exposure in case-control studies with pooling." Stat. Med. 31: 2461–2472.


vandomed/meuc documentation built on May 12, 2019, 6:17 p.m.