Linearly re-parameterize the model to be less sensitive to rounding errors

preconditionFit(fit, estType = c("full", "posthoc", "none"), ntry = 10L)

## Arguments

fit A nlmixr fit to be preconditioned Once the fit has been linearly reparametrized, should a "full" estimation, "posthoc" estimation or simply a estimation of the covariance matrix "none" before the fit is updated number of tries before giving up on a pre-conditioned covariance estimate

## Value

A nlmixr fit object that was preconditioned to stabilize the variance/covariance calculation

## References

Aoki Y, Nordgren R, Hooker AC. Preconditioning of Nonlinear Mixed Effects Models for Stabilisation of Variance-Covariance Matrix Computations. AAPS J. 2016;18(2):505-518. doi:10.1208/s12248-016-9866-5