Extract the Condition Number from a NONMEM Listing File

Computes the condition number of the correlation matrix of parameter estimates as the ratio of the largest to smallest eigenvalue. A condition number above 1000 typically indicates numerical difficulties in parameter estimation.

Usage

fetch_condn(lst, digits = NA)

Arguments

lst

An object of class "lst" from read_lst_file().

digits

Integer or NA. Rounding for the condition number. Default NA.

Value

A single numeric value (the condition number), or NA_real_ if the eigenvalue section is absent.

Details

Returns NA gracefully when no covariance step was run.

Examples

path <- system.file("testdata", "full_cov.lst", package = "lstparsR")
lst  <- read_lst_file(path)
fetch_condn(lst)
#> [1] 23.30882