fetch.rho.b: Function to transform f(rho) back to rho

In StratSel: Strategic Selection Estimator

Description

The model has a correlation parameter which is estimated and theoretically bound between -1 and +1. To ensure that the estimated parameters are within the theoretical bounds a transformation is necessary. The chosen transformation is:

f(ρ): ρ = 2/(1-exp(-θ))- 1

Whereas ρ is the actual correlation coefficient and θ is the parameter we estimate in the model. This parametrization has been worked into the likelihood function and ensures that ρ will be between -1 and +1.

Usage

fetch.rho.b(b)

Arguments

b	The vector of estimated coefficients (β) whereas the last element is the transformed correlation coefficient (here: θ).

Details

This function is for internal use but documented as a regular function to enable any user to assess the estimator and its functionality.

Value

The function returns the correct estimate for ρ.

Note

We want to estimate ρ but because it is theoretically bound, we estimate θ which is not bound can range from -∞ to +∞.

Author(s)

Lucas Leemann [e-mail]

See Also

StratSel

Examples

test <- c(1,1,-2.35)
fetch.rho.b(test)

StratSel documentation built on May 2, 2019, 11:11 a.m.