pInf: Parameter Inference for classic nonlinear regression.
Description
Parameter inference for classic nonliner regression. It work same as parInfer method of nl.fitt, calculate covariance matrix of parameters and their confidence interval using gradient as design matrix.
Covariance matrix of nonlinear model function parameters.
corrmat
Correlation matrix of nonlinear model function parameters.
parstdev:
Standard deviation of nonlinear model function parameter. It is square root of diagonal of covmat.
CI:
Confidence interval for nonlinear model function parameter.
Details
For computing the covariance matrix of a nonlinear regression parameter, the gradient of function with respect to parameters is consider as design matrix and linear regression formulas apply for computing covariances and confidence intervals.
References
Seber, G., A. F. and Wild, C. J. (2003). Nonlinear Regression. New York: John Wiley & Sons, Inc.
Lim, C., Sen, P. K., Peddada, S. D. (2010). Statistical inference in nonlinear regression under heteroscedasticity. Sankhya B 72:202-218.