Function: inequalities - plot regions defined by inequalities

Calling Sequence:

inequalities( ineqs, xvar = a .. b, yvar = c .. d, options )

Parameters:

ineqs - one inequality or equation or a set of inequalities and equations
xvar - name for the x axis variable

a, b - bounds for xvar (real constants)

yvar - name for the y axis variable

c, d - bounds for yvar (real constants)

options - (optional) see below

Description:

This is similar to inequal in the plots package, but allows nonlinear inequalities and equations.

The plot consists of four elements:
feasible region - the region where all inequalities are satisfied 
excluded region - the region where at least one inequality is violated
open lines - curves representing the boundaries of strict ( < ) inequalities
closed lines - curves representing the boundaries of non-strict ( <= ) inequalities, as well as equations.

Use the options optionsfeasible = (...) , optionsexcluded = (...) , optionsopen = (...) , optionsclosed = (...) to control the appearance of each of these elements. The defaults are optionsfeasible = (colour = green) , optionsexcluded = (colour = white) , optionsopen = (colour = red, linestyle=2) , optionsclosed = (colour = blue, linestyle = 0) .

Non-Cartesian coordinates are supported, using the coords option.

Other two-dimensional plotting options can be used.

This function is part of the Maple Advisor Database library, and must be loaded before use by the command readlib(inequalities);

> readlib(inequalities):

> inequalities({x+y>0, x^2 + y^2 <=3}, x=-2..2, y=-2..2 );

> inequalities({x+y>0, x^2-y^2<=1, y=2}, x=-3..3, y=-3..3,
optionsfeasible=(color=cyan),
optionsopen=(color=blue, thickness=2),
optionsclosed=(color=red, thickness=3),
optionsexcluded=(color=aquamarine) );

> inequalities(r^2 >= cos(2*theta), r = 0 .. 1.5, theta = 0 .. 2*Pi, coords=polar, labels = [``,``],axes=box);

See also:

coords , inequal , plot(options)

Maple Advisor Database R. Israel 1998