FindHillBounds {dr4pl}

FindHillBounds

Description

Compute the Hill bounds based on initial parameter estimates and data.

Usage

FindHillBounds(x, y, theta, use.Hessian = FALSE, level = 0.9999)

Arguments

x

Vector of doses.

y

Vector of responses.

theta

Parameters of a 4PL model.

use.Hessian

Indicator of whether the Hessian matrix (TRUE) or the gradient vector is used in confidence interval computation.

level

Confidence level to be used in computing the Hill bounds.

Details

This function computes the Hill bounds based on initial parameter estimates and data. It basically computes the confidence intervals of the true parameters based on the variance-covariance matrix of a given initial parameter estimates. The half of a hessian matrix is used as a variance-covariance matrix. If matrix inversion of the variance-covariance matrix is infeasible, a variation of the method in Wang et al. (2010) is used. The parameter level is only for simulation.

Value

Data frame whose first column represents the bounds on the IC50 parameter in log 10 scale and second column represents the bounds on the slope parameter.

Author(s)

Hyowon An, [e-mail].

References

Higham NJ (2002). “Computing the nearest correlation matrix—a problem from finance.” IMA J. Numer. Anal., 22(3), 329–343. ISSN 0272-4979, doi: 10.1093/imanum/22.3.329, http://dx.doi.org.libproxy.lib.unc.edu/10.1093/imanum/22.3.329. Wang Y, Jadhav A, Southal N, Huang R, Nguyen DT (2010). “A grid algorithm for high throughput fitting of dose-response curve data.” Curr Chem Genomics, 4, 57–66.

See Also

FindInitialParms, FindLogisticGrids.