invert.lsq: Least squares model inversion

In ashiklom/PEcAnRTM: PEcAn functions used for radiative transfer modeling

Description

Performs a least-squares inversion of an arbitrary radiative transfer model (passed as an R function). The inversion attempts to minimize the sum of residual least squares between modeled and observed spectra via the Levenberg-Marquardt algorithm (nls.lm function from the minpack.lm package).

Usage

invert.lsq(observed, inits, model, lower = NULL, upper = NULL)

Arguments

observed	Vector of observations (e.g. a reflectance spectrum).
inits	Vector of initial conditions for the parameters.
model	An R function that calls the RTM and returns the error to be minimized. Be sure to include constants here.
lower	Lower bounds on parameters (default=NULL, which means -Inf).
uppper	Upper bounds on parameters (default=NULL, which means +Inf).

Author(s)

Alexey Shiklomanov

ashiklom/PEcAnRTM documentation built on March 7, 2020, 7:46 a.m.