phaseR (version 2.0)

example9: Example ODE System 9

Description

The derivative function of an example two-dimensional autonomous ODE system.

Usage

example9(t, y, parameters)

Arguments

t

The value of , the independent variable, to evaluate the derivative at. Should be a single number.

y

The values of and , the dependent variables, to evaluate the derivative at. Should be a vector of length two.

parameters

The values of the parameters of the system. Not required here.

Value

Returns a list containing the values of the two derivatives at .

Details

example9 evaluates the derivatives of the following coupled ODE system at the point :

Its format is designed to be compatible with ode from the deSolve package.

See Also

ode

Examples

# NOT RUN {
# Plot the velocity field, nullclines and several trajectories
example9.flowField  <- flowField(example9,
                                 xlim = c(-3, 3),
                                 ylim = c(-3, 3),
                                 points = 19,
                                 add = FALSE)
y0                  <- matrix(c(1, 0, -3, 2,
                                2, -2, -2, -2), 4, 2,
                              byrow = TRUE)
example9.nullclines <- nullclines(example9,
                                  xlim = c(-3, 3),
                                  ylim = c(-3, 3))
example9.trajectory <- trajectory(example9,
                                  y0 = y0,
                                  tlim = c(0, 10))
example9.manifolds  <- drawManifolds(example9,
                                     y0 = c(0, 0),
                                     tend = 10,
                                     col = c("green", "red"),
                                     add.legend = TRUE)
# Determine the stability of the equilibrium point
example9.stability  <- stability(example9,
                                 ystar = c(0, 0))
# }