Open-File Report 2012–1181
AbstractThis report presents the mathematical expressions and the computational techniques required to compute maximum-likelihood estimates for the parameters of the National Descriptive Model of Mercury in Fish (NDMMF), a statistical model used to predict the concentration of methylmercury in fish tissue. The expressions and techniques reported here were prepared to support the development of custom software capable of computing NDMMF parameter estimates more quickly and using less computer memory than is currently possible with available general-purpose statistical software. Computation of maximum-likelihood estimates for the NDMMF by numerical solution of a system of simultaneous equations through repeated Newton-Raphson iterations is described. This report explains the derivation of the mathematical expressions required for computational parameter estimation in sufficient detail to facilitate future derivations for any revised versions of the NDMMF that may be developed. |
First posted December 14, 2012 For additional information contact: Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge. |
Donato, D.I., 2012, Computing maximum-likelihood estimates for parameters of the National Descriptive Model of Mercury in Fish: U.S. Geological Survey Open-File Report 2012–1181, 15 p., available only at http://pubs.usgs.gov/of/2012/1181.
Introduction
Maximum-Likelihood Estimates for a Linear Model
Maximum-Likelihood Estimates for the National Descriptive Model of Mercury in Fish
Numerical Computation of Parameter Estimates for the National Descriptive Model of Mercury in Fish
Summary
References Cited
Appendix