singular_conv_tol
Singular convergence tolerance
Specification
Alias: None
Arguments: REAL
Default: -1. (use NL2SOL internal default)
Description
singular_conv_tol
(NL2SOL’s sctol) is the singular convergence tolerance, which works
in conjunction with singular_radius to test for
underdetermined least-squares problems (stop when the relative
reduction yet possible in the sum of squares appears less then
singular_conv_tol for steps of scaled length at most singular_radius).
The internal default is a function of machine epsilon
(as limited by function_precision). The default is selected with a value of -1.

