nlsr.control: nlsr.control

In nlsr: Functions for Nonlinear Least Squares Solutions - Updated 2022

nlsr.control

Description

Set and provide defaults of controls for package nlsr

Usage

nlsr.control(control)

Arguments

control

A list of controls. If missing, the defaults are provided. See below. If a named control is provided, e.g., via a call ctrllist<- nlsr.control(japprox="jand"), then that value is substituted for the default of the control in the FULL list of controls that is returned. NOTE: at 2022-6-17 there is NO CHECK FOR VALIDITY The set of possible controls to set is as follows, and is returned.

Value

femax	INTEGER limit on the number of evaluations of residual function Default 10000.
japprox	CHARACTER name of the Jacobian approximation to use Default NULL, since we try to use analytic gradient
jemax	INTEGER limit on the number of evaluations of the Jacobian Default 5000
lamda	REAL initial value of the Marquardt parameter Default 0.0001 Note: mis-spelling as in JNMWS, kept as historical serendipity.
lamdec	REAL multiplier used to REDUCE lambda (0 < lamdec < laminc) Default 4, so lamda <- lamda * (lamdec/laminc)
laminc	REAL multiplier to INCREASE lambda (1 < laminc Default 10
nbtlim	if stepredn > 0, then maximum number of backtrack loops (in addition to default evaluation); Default 6
ndstep	REAL stepsize for numerical Jacobian approximation Default 1e-7
offset	REAL A value used to test for numerical equality, i.e. a and b are taken equal if (a + offset) == (b + offset) Default 100.
phi	REAL Factor used to add unit Marquardt stabilization matrix in Nash modification of LM method. Default 1
prtlvl	INTEGER The higher the value, the more intermediate output is provided. Default 0
psi	REAL Factor used to add scaled Marquardt stabilization matrix in Nash modification of LM method. Default 0
rofftest	LOGICAL If TRUE, perform (safeguarded) relative offset convergence test Default TRUE
scaleOffset	a positive constant to be added to the denominator sum-of-squares in the relative offset convergence criteria. Default 0
smallsstest	LOGICAL. If TRUE tests sum of squares and terminates if very small. Default TRUE
stepredn	REAL Factor used to reduce the stepsize in a Gauss-Newton algorithm (Hartley's method). 0 means NO backtrack. Default 0
watch	LOGICAL to provide a pause at the end of each iteration for user to monitor progress. Default FALSE

Author(s)

J C Nash 2014-7-16 revised 2022-11-22 nashjc _at_ uottawa.ca

nlsr documentation built on Sept. 8, 2023, 5:48 p.m.