Function to calculate endpoints for further use from kinetic models fitted -with mkinfit

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This function calculates DT50 and DT90 values as well as formation fractions -from kinetic models fitted with mkinfit. If the SFORB model was specified -for one of the parents or metabolites, the Eigenvalues are returned. These -are equivalent to the rate constants of the DFOP model, but with the -advantage that the SFORB model can also be used for metabolites.

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endpoints(fit, covariates = NULL, covariate_quantile = 0.5)

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Arguments

fit: An object of class mkinfit, nlme.mmkin or saem.mmkin, or -another object that has list components mkinmod containing an mkinmod -degradation model, and two numeric vectors, bparms.optim and bparms.fixed, -that contain parameter values for that model.
covariates: Numeric vector with covariate values for all variables in -any covariate models in the object. If given, it overrides 'covariate_quantile'.
covariate_quantile: This argument only has an effect if the fitted -object has covariate models. If so, the default is to show endpoints -for the median of the covariate values (50th percentile).

Value

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A list with a matrix of dissipation times named distimes, and, if -applicable, a vector of formation fractions named ff and, if the SFORB model -was in use, a vector of eigenvalues of these SFORB models, equivalent to -DFOP rate constants

Details

Additional DT50 values are calculated from the FOMC DT90 and k1 and k2 from -HS and DFOP, as well as from Eigenvalues b1 and b2 of any SFORB models

Note

The function is used internally by summary.mkinfit, -summary.nlme.mmkin and summary.saem.mmkin.

Author

Johannes Ranke

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Examples


-  fit <- mkinfit("FOMC", FOCUS_2006_C, quiet = TRUE)
-  endpoints(fit)
-#> $distimes
-#>            DT50    DT90 DT50back
-#> parent 1.785233 15.1479 4.559973
-#> 
-  # \dontrun{
-    fit_2 <- mkinfit("DFOP", FOCUS_2006_C, quiet = TRUE)
-    endpoints(fit_2)
-#> $distimes
-#>            DT50     DT90 DT50back  DT50_k1  DT50_k2
-#> parent 1.886925 21.25106 6.397207 1.508293 38.83438
-#> 
-    fit_3 <- mkinfit("SFORB", FOCUS_2006_C, quiet = TRUE)
-    endpoints(fit_3)
-#> $ff
-#> parent_free 
-#>           1 
-#> 
-#> $SFORB
-#> parent_b1 parent_b2  parent_g 
-#> 0.4595574 0.0178488 0.8539454 
-#> 
-#> $distimes
-#>            DT50     DT90 DT50back DT50_parent_b1 DT50_parent_b2
-#> parent 1.886925 21.25106 6.397208       1.508293       38.83438
-#> 
-  # }
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