LinkFuncSkeleton: Skeleton of Link Function
In itamarfaran/corrpops: Analysis of populations of correlation matrices

Skeleton of link function consumed by estimate_model. has the following elements:

name: optional, a string specifing the link function's name
func: mandatory, a function with input t (theta), a vectorized correlation matrix, a (alpha) and d, the number of columns in alpha. the output would be a correlation matrix with alpha effect
inverse: optinal, a function with input a, that inverts alpha. for example, of we specify func to calculate exp(a), inverse would be log(a)
rev_func: mandatory, a function with input datamatrix, a vectorized array of correlation matrices, a (alpha) and d, the number of columns in alpha. the output would be the array with the alpha effect reversed
null_value: mandatory, the null value of the link function