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

+ +

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.

+ +

Usage

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

+ +

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

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

+ +

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
+#> 
+  # }
+
+