nlme version used for fitting: Dummy 0.0 for testing mkin version used for pre-fitting: Dummy 0.0 for testing R version used for fitting: Dummy R version for testing Date of fit: Dummy date for testing Date of summary: Dummy date for testing Equations: d_parent/dt = - ((k1 * g * exp(-k1 * time) + k2 * (1 - g) * exp(-k2 * time)) / (g * exp(-k1 * time) + (1 - g) * exp(-k2 * time))) * parent Data: 270 observations of 1 variable(s) grouped in 15 datasets Model predictions using solution type analytical Fitted in test time 0 s using 5 iterations Variance model: Two-component variance function Mean of starting values for individual parameters: parent_0 log_k1 log_k2 g_qlogis 100.2 -2.6 -4.2 0.1 Fixed degradation parameter values: None Results: AIC BIC logLik 1410 1446 -695 Optimised, transformed parameters with symmetric confidence intervals: lower est. upper parent_0 98.7 100.1 101.5 log_k1 -2.9 -2.7 -2.5 log_k2 -4.2 -4.1 -4.0 g_qlogis -0.7 -0.4 -0.2 Correlation: pr_0 lg_1 lg_2 log_k1 0.3 log_k2 0.1 0.2 g_qlogis -0.1 -0.5 -0.4 Random effects: Formula: list(parent_0 ~ 1, log_k1 ~ 1, log_k2 ~ 1, g_qlogis ~ 1) Level: ds Structure: Diagonal parent_0 log_k1 log_k2 g_qlogis Residual StdDev: 2 0.3 0.2 0.2 1 Variance function: Structure: Constant plus proportion of variance covariate Formula: ~fitted(.) Parameter estimates: const prop 0.9227472 -0.0480500 Backtransformed parameters with asymmetric confidence intervals: lower est. upper parent_0 98.69 1e+02 1e+02 k1 0.06 7e-02 9e-02 k2 0.01 2e-02 2e-02 g 0.34 4e-01 5e-01 Estimated disappearance times: DT50 DT90 DT50back DT50_k1 DT50_k2 parent 23 111 33 10 43