NumericalCheck function

The numerical predictive checks

This function calculates the numerical predictive checks for each prediction level. For a given level of prediction, the predicted interval is calculated using the simulated data, and the number of observed data below the predicted interval is counted. The expected number of points below the predicted interval is also calculated and compared to the observed number.

NumericalCheck(orig_data,
               sim_data,
               N_xbin = NULL,
               pred.level = c(0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9),
               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.
• pred.level: Numeric vector of probabilities.
• 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 result of numerical predictive check

Examples

data(origdata)
data(simdata)
NumericalCheck(origdata,simdata,N_xbin=8)$NPC

References

Holford N, & Karlsson M. (2008). "A tutorial on visual predictive checks, abstr 1434." Annual Meeting of the Populations Approach Group in Europe. www.page-meeting.org. 2008.

Harling, Uekcert, K. 2018. VPC and NPC User Guide. ICON plc.

https://github.com/UUPharmacometrics/PsN/releases/download/4.9.0/vpc_npc_userguide.pdf.