showConstraint {DVHmetrics} R Documentation

## Display constraints for cumulative dose-volume histograms

### Description

Displays quality assurance constraints for cumulative dose-volume histograms: Either one diagram per patient - including multiple structures. Or one diagram per structure - including multiple patients.

### Usage

showConstraint(x, constr, byPat=TRUE, rel=TRUE, guessX=TRUE, guessY=TRUE,
thresh=1, show=TRUE, visible=FALSE)

## S3 method for class 'DVHs'
showConstraint(x, constr, byPat=TRUE, rel=TRUE, guessX=TRUE, guessY=TRUE,
thresh=1, show=TRUE, visible=FALSE)

## S3 method for class 'DVHLst'
showConstraint(x, constr, byPat=TRUE, rel=TRUE, guessX=TRUE, guessY=TRUE,
thresh=1, show=TRUE, visible=FALSE)

## S3 method for class 'DVHLstLst'
showConstraint(x, constr, byPat=TRUE, rel=TRUE, guessX=TRUE, guessY=TRUE,
thresh=1, show=TRUE, visible=FALSE)


### Arguments

 x A single DVH (object of class DVHs), multiple DVHs from one patient/structure (object of class DVHLst), or multiple DVHs from many patients/structures (object of class DVHLstLst). See readDVH. See Details. constr One or more constraints - given as a character vector or as a data.frame. See checkConstraint for their definition. byPat logical. Relevant if multiple DVHs are given. If x has class DVHLstLst: byPat=TRUE means that one diagram shows DVHs from one patient with multiple structures. byPat=FALSE means that one diagram shows DVHs for one structure from multiple patients. rel logical. Show relative volume? guessX logical. Try to guess the best x-axis limits for better visibility of main DVH range? If FALSE, x-axis runs from 0 to maximum dose. If TRUE, x-axis runs from 0 to dose value where volume approaches 0. If a single number is given, it is interpreted as the maximum value. If a vector of two numbers is given, it is interpreted as the range of the axis. guessY logical. Try to guess the best y-axis limits? If a single number is given, it is interpreted as the maximum value. If a vector of two numbers is given, it is interpreted as the range of the axis. thresh numeric value. Relative volume threshold used with guessX=TRUE. Clip x-axis (+10%) such that the "highest" DVH is cut off at this relative volume. show logical. If TRUE, diagrams are shown, if FALSE diagrams are not shown - only ggplot diagram objects are silently returned. visible logical. Return ggplot diagram object visibly or invisibly. show=FALSE with visible=TRUE is useful for zooming in shiny apps.

### Details

Constraints are shown as points in the cumulative DVH with an additional arrow indicating where the cumulative DVH curve should lie relative to the constraint. On each DVH curve, the point with the minimal Euclidean distance to the constraint is indicated. Note that, visually, this point only has the minimal apparent distance if the aspect ratio of the diagram is 1.

If multiple diagrams are produced, they are shown in the same graphics device. If interactive inspection is required, make sure you use an R development environment that saves previous diagrams and allows navigating between them - e.g., RStudio or OpenAnalytics Architect.

### Value

Silently returns a ggplot diagram object, or - when multiple diagrams are constructed - a list of ggplot diagram objects.

checkConstraint, saveDVH

### Examples

data(dataMZ)

# define constraints
constr <- data.frame(
patID=c("P123", "P234"),
structure=c("HEART", "*"),
constraint=c("D1CC < 20Gy", "V10% > 8CC"),
stringsAsFactors=FALSE)       # this is important
showConstraint(dataMZ, constr=constr, byPat=FALSE)


[Package DVHmetrics version 0.4.2 Index]