coverageDetailplot function

The detailed coverage plot

This function draws the detailed coverage plot for the specific prediction level to check over or under estimate regions in each prediction level. The percentages of observations above the prediction interval are calculated in each bin of the independent variable. Additionally, the percentages of observations below the prediction interval are calculated. The white dots in the plot represent the expected percentages.

coverageDetailplot(orig_data,
                  sim_data,
                  N_xbin = NULL,
                  predL = 0.5,
                  conf.level = 0.95,
                  X_name = "TIME",
                  Y_name = "DV",
                  MissingDV = NULL,
                  Kmethod = "cluster",                
                  maxK = NULL,
                  beta = 0.2,
                  lambda = 0.3,
                  R = 4,
                  C1 = 2.5,
                  C2 = 7.8, ...)

Arguments

• orig_data: A data frame of original data with X and Y variable.
• sim_data: A matrix of simulated data with only Y values collected.
• N_xbin: Number of bins in X variable. If NULL, optimal number of bins are automatically calcuated using optK function.
• predL: Scalar of probability
• conf.level: Confidence level of the interval.
• X_name: Name of X variable in orig_data (usually "TIME" in pharmacokinetic data).
• Y_name: Name of Y variable in orig_data (usually "DV" in pharmacokinetic data)
• MissingDV: Name of missing indicator variable in orig_data, which have value 1 if missing, value 0 otherwise. (usually "MDV" in pharmacokinetic data).
• Kmethod: The way to calculate the penalty in automatic binning."cluster" or "kernel".
• maxK: The maximum number of bins
• beta: Additional parameter for automatic binning, used in optK function.
• lambda: Additional parameter for automatic binning, used in optK function.
• R: Additional parameter for automatic binning, used in optK function.
• C1: Additional parameter for automatic binning, used in optK function.
• C2: Additional parameter for automatic binning, used in optK function.
• ...: Arguments to be passed to methods.

Returns

the detailed coverage plot

Examples

data(origdata)
data(simdata)
coverageDetailplot(origdata,simdata,predL=0.5,N_xbin=8)

References

Post, T. M., et al. (2008) Extensions to the visual predictive check for facilitate model performance evaluation, Journal of pharmacokinetics and pharmacodynamics, 35(2), 185-202