mosaicCalc (version 0.6.4)

inequality_constraint: Graphics for constraints

Description

These functions are intended to annotate contour plots with constraint regions. Inequality constraints are shaded where the constraint is NOT satisfied. Equality constraints are shaded in a small region near where the constraint is satisfied.

Usage

inequality_constraint(
  previous = NULL,
  tilde,
  domain,
  npts = 100,
  fill = "blue",
  alpha = 1
)
equality_constraint(
  previous = NULL,
  tilde,
  domain,
  npts = 100,
  fill = "blue",
  alpha = 1
)

Value

ggplot2 graphics layers

Arguments

previous

can be ignored by user. It supports the pipe syntax for layering graphics.

tilde

a tilde expression specifying the constraint. For an inequality constraint this should be a logical expression that is TRUE where the constraint is satisfied. For an equality constraint, the left-hand side of the tilde expression should be zero where the constraint IS satisfied.

domain

as in contour_plot(), the domain over which to graph the constraint

npts

a number specifying how finely to divide the domain in each direction. Default is 100, but this gives a discernably pixelated appearance to the shading. 200 or 300 is more appropriate for publication-quality graphics.

fill

the color to use for shading

alpha

the opacity of the shading

Examples

inequality_constraint(x + y > 2 ~ y + x, domain(y=0:3, x=0:2))
equality_constraint(x + y - 2 ~ y + x, domain(y=0:3, x=0:2), npts=200, alpha=.3, fill="red")