Exponential parameter transformation — transform1 • ameras

Applies exponential transformation \(f(\theta_i)=\exp(\theta_i)+L_i\) to one or multiple components of parameter vector \(\bm \theta\), where \(L_i\) are lower limits that can be different for each component

Usage

transform1(params, index.t=1:length(params), lowlimit=rep(0,length(index.t)), 
  boundcheck=FALSE, boundtol=1e-3, ... )

Arguments

params: full input parameter vector
index.t: indices of parameters to be transformed (default all)
lowlimit: lower limits to be applied (default zero), where the k-th component of lowlimit is applied to the k-th index in index.t
boundcheck: whether to produce a warning when any of the transformed parameters are within boundtol of lowlimit
boundtol: tolerance for producing a warning for reaching the boundary
...: not used

Value

Transformed parameter vector.

Examples

params <- c(.1, .5, 1)
transform1(params, lowlimit=c(0, -1, 1))
#> [1] 1.1051709 0.6487213 3.7182818