Lists model equations, initial parameter values, optimised parameters with some uncertainty statistics, the chi2 error levels calculated according to FOCUS guidance (2006) as defined therein, formation fractions, DT50 values and optionally the data, consisting of observed, predicted and residual values.
an object of class mkinfit.
logical, indicating whether the data should be included in the summary.
logical, indicating whether DT50 and DT90 values should be included.
error level for confidence interval estimation from t distribution
optional arguments passed to methods like print.
an object of class summary.mkinfit.
Number of digits to use for printing
The summary function returns a list with components, among others
The mkin and R versions used
The dates where the fit and the summary were produced
The differential equations used in the model
Was maximum or minimum use made of formation fractions
Optimised and backtransformed parameters
The data (see Description above).
The starting values and bounds, if applicable, for optimised parameters.
The values of fixed parameters.
The chi2 error levels for each observed variable.
All backtransformed ODE parameters, for use as starting parameters for related models.
Error model parameters.
The estimated formation fractions derived from the fitted model.
The DT50 and DT90 values for each observed variable.
If applicable, eigenvalues and fractional eigenvector component g of SFORB systems in the model.
The print method is called for its side effect, i.e. printing the summary.
FOCUS (2006) “Guidance Document on Estimating Persistence and Degradation Kinetics from Environmental Fate Studies on Pesticides in EU Registration” Report of the FOCUS Work Group on Degradation Kinetics, EC Document Reference Sanco/10058/2005 version 2.0, 434 pp, http://esdac.jrc.ec.europa.eu/projects/degradation-kinetics
summary(mkinfit("SFO", FOCUS_2006_A, quiet = TRUE))
#> mkin version used for fitting: 1.2.6
#> R version used for fitting: 4.3.1
#> Date of fit: Mon Oct 30 09:39:49 2023
#> Date of summary: Mon Oct 30 09:39:49 2023
#>
#> Equations:
#> d_parent/dt = - k_parent * parent
#>
#> Model predictions using solution type analytical
#>
#> Fitted using 131 model solutions performed in 0.02 s
#>
#> Error model: Constant variance
#>
#> Error model algorithm: OLS
#>
#> Starting values for parameters to be optimised:
#> value type
#> parent_0 101.24 state
#> k_parent 0.10 deparm
#>
#> Starting values for the transformed parameters actually optimised:
#> value lower upper
#> parent_0 101.240000 -Inf Inf
#> log_k_parent -2.302585 -Inf Inf
#>
#> Fixed parameter values:
#> None
#>
#> Results:
#>
#> AIC BIC logLik
#> 55.28197 55.5203 -24.64099
#>
#> Optimised, transformed parameters with symmetric confidence intervals:
#> Estimate Std. Error Lower Upper
#> parent_0 109.200 3.70400 99.630 118.700
#> log_k_parent -3.291 0.09176 -3.527 -3.055
#> sigma 5.266 1.31600 1.882 8.649
#>
#> Parameter correlation:
#> parent_0 log_k_parent sigma
#> parent_0 1.000e+00 5.428e-01 1.642e-07
#> log_k_parent 5.428e-01 1.000e+00 2.507e-07
#> sigma 1.642e-07 2.507e-07 1.000e+00
#>
#> Backtransformed parameters:
#> Confidence intervals for internally transformed parameters are asymmetric.
#> t-test (unrealistically) based on the assumption of normal distribution
#> for estimators of untransformed parameters.
#> Estimate t value Pr(>t) Lower Upper
#> parent_0 109.20000 29.47 4.218e-07 99.6300 118.70000
#> k_parent 0.03722 10.90 5.650e-05 0.0294 0.04712
#> sigma 5.26600 4.00 5.162e-03 1.8820 8.64900
#>
#> FOCUS Chi2 error levels in percent:
#> err.min n.optim df
#> All data 8.385 2 6
#> parent 8.385 2 6
#>
#> Estimated disappearance times:
#> DT50 DT90
#> parent 18.62 61.87
#>
#> Data:
#> time variable observed predicted residual
#> 0 parent 101.24 109.153 -7.9132
#> 3 parent 99.27 97.622 1.6484
#> 7 parent 90.11 84.119 5.9913
#> 14 parent 72.19 64.826 7.3641
#> 30 parent 29.71 35.738 -6.0283
#> 62 parent 5.98 10.862 -4.8818
#> 90 parent 1.54 3.831 -2.2911
#> 118 parent 0.39 1.351 -0.9613