Ancillary Parameters for Controlling the Fit in dosresmeta Models
Ancillary Parameters for Controlling the Fit in dosresmeta Models
This internal function sets the parameter options used for fitting dose-response meta-analytical models, commonly to pre-specified default values. It is usually internally called by dosresmeta.fit.
optim: list of parameters passed to the control argument of the function optim, which performs the quasi-Newton optimization in likelihood-based random-effects models. See optim.
showiter: logical. If TRUE, the progress of iterative optimization is shown.
maxiter: positive interger value. Maximum number of iterations in methods involving optimization procedures.
initPsi: either a matrix or a vector of its lower triangular elements (with diagonal, taken by column) from which starting values of the parameters of the between-study (co)variance matrix are derived, used in the optimization procedure for likelihood-based random-effects models. If NULL (the default, and recommended), the starting value is created internally through an iterative generalized least square algorithm.
igls.iter: number of iteration of the iterative generalized least square algorithm to be run in the hybrid optimization procedure of linkelihood-based models to provide the starting value.
gr: indicates if the gradient of the (re)ml likelihood should be provided. FALSE by default.
reltol: relative convergence tolerance in methods involving optimization procedures. The algorithm stops if it is unable to reduce the value by a factor of reltol∗(abs(val)+reltol) at a step.
set.negeigen: positive value. Value to which negative eigenvalues are to be set in estimators where such method is used to force positive semi-definiteness of the estimated between-study (co)variance matrix.
Returns
A list with components named as the arguments.
Examples
## Loading datadata("alcohol_cvd")## print the iterations (see ?optim) and change the default for starting valuesdosresmeta(formula = logrr ~ dose, type = type, id = id, se = se, cases = cases, n = n, data = alcohol_cvd, proc ="1stage", control = list(showiter =TRUE, igls.iter =20))
References
Gasparrini, A., Armstrong, B., Kenward, M. G. (2012). Multivariate meta-analysis for non-linear and other multi-parameter associations. Statistics in Medicine, 31(29), 3821-3839.