deltaInverse: Calculate inverse (dose-finding) intervals, using local... In cir: Centered Isotonic Regression and Dose-Response Utilities

Description

Calculate left-bound to right-bound intervals for the dose point estimates, using local slopes at design points (places where observations exist) to invert the forward lower-upper bounds.

Usage

 1 2 3 4 5 6 7 8 deltaInverse( isotPoint, target = NULL, intfun = morrisCI, conf = 0.9, adaptiveCurve = FALSE, ... )

Arguments

 isotPoint The output of an estimation function such as cirPAVA,doseFind, with the option full=TRUE. Should be at least a list of 3 doseResponse objects named input, output, shrinkage. target A vector of target response rate(s), for which the interval is needed. If NULL (default), interval will be returned for the point estimates at design points (e.g., if the forward point estimate at \$x_1\$ is 0.2, then the first returned interval is for the 20th percentile). intfun the function to be used for initial (forward) interval estimation. Default morrisCI (see help on that function for additional options). conf numeric, the interval's confidence level as a fraction in (0,1). Default 0.9. adaptiveCurve logical, should the CIs be expanded by using a parabolic curve between estimation points rather than straight interpolation (default FALSE)? Recommended when adaptive design was used and target is not 0.5. ... additional arguments passed on to quickIsotone

Details

The Delta method in this application boils down to dividing the distance to the forward (vertical) bounds, by the slope, to get the left/right interval width. Slope estimates are performed by slope. An alternative method (dubbed "global") is hard-coded into quickInverse.

Value

two-column matrix with the left and right bounds, respectively