Plot the convex hull of a set of points in 2D.

Usage

plotHull2D(
  pts,
  drawPoints = FALSE,
  drawLines = TRUE,
  drawPolygons = TRUE,
  addText = FALSE,
  addRays = FALSE,
  direction = 1,
  drawPlot = TRUE,
  drawBBoxHull = FALSE,
  m = apply(pts, 2, min) - 5,
  M = apply(pts, 2, max) + 5,
  ...
)

Arguments

pts

A matrix with a point in each row.

drawPoints

Draw the points.

drawLines

Draw lines of the facets.

drawPolygons

Fill the hull.

addText

Add text to the points. Currently coord (coordinates), rownames (rownames) and both supported or a vector with text.

addRays

Add the ray defined by direction.

direction

Ray direction. If i'th entry is positive, consider the i'th column of pts plus a value greater than on equal zero (minimize objective $i$). If negative, consider the i'th column of pts minus a value greater than on equal zero (maximize objective $i$).

drawPlot

Draw the ggplot. Set to FALSE if you want to combine hulls in a single plot.

drawBBoxHull

If addRays then draw the hull areas hitting the bounding box also.

m

Minimum values of the bounding box.

M

Maximum values of the bounding box.

...

Further arguments passed on the the ggplot plotting functions. This must be done as lists. Currently the following arguments are supported:

argsGeom_point: A list of arguments for ggplot2::geom_point.
argsGeom_path: A list of arguments for ggplot2::geom_path.
argsGeom_polygon: A list of arguments for ggplot2::geom_polygon.
argsGeom_label: A list of arguments for ggplot2::geom_label.

Value

The ggplot object if drawPlot = TRUE; otherwise, a list of ggplot components.

Examples

library(ggplot2)
pts<-matrix(c(1,1), ncol = 2, byrow = TRUE)
plotHull2D(pts)

pts1<-matrix(c(2,2, 3,3), ncol = 2, byrow = TRUE)
plotHull2D(pts1, drawPoints = TRUE)

plotHull2D(pts1, drawPoints = TRUE, addRays = TRUE, addText = "coord")

plotHull2D(pts1, drawPoints = TRUE, addRays = TRUE, addText = "coord", drawBBoxHull = TRUE)

plotHull2D(pts1, drawPoints = TRUE, addRays = TRUE, direction = -1, addText = "coord")

pts2<-matrix(c(1,1, 2,2, 0,1), ncol = 2, byrow = TRUE)
plotHull2D(pts2, drawPoints = TRUE, addText = "coord")

plotHull2D(pts2, drawPoints = TRUE, addRays = TRUE, addText = "coord")

plotHull2D(pts2, drawPoints = TRUE, addRays = TRUE, direction = -1, addText = "coord")

## Combine hulls
ggplot() +
  plotHull2D(pts2, drawPoints = TRUE, addText = "coord", drawPlot = FALSE) +
  plotHull2D(pts1, drawPoints = TRUE, drawPlot = FALSE) +
  gMOIPTheme() +
  xlab(expression(x[1])) +
  ylab(expression(x[2]))


# Plotting an LP
A <- matrix(c(-3,2,2,4,9,10), ncol = 2, byrow = TRUE)
b <- c(3,27,90)
obj <- c(7.75, 10)
pts3 <- cornerPoints(A, b)
plotHull2D(pts3, drawPoints = TRUE, addText = "coord", argsGeom_polygon = list(fill = "red"))