Example ODE system 11
The derivative function of an example two-dimensional autonomous ODE system.
example11(t, y, parameters)
t
: The value of , the independent variable, to evaluate the derivative at. Should be a numeric
vector
of length
one.
y
: The values of and , the dependent variables, to evaluate the derivative at. Should be a numeric
vector
of length
two.
parameters
: The values of the parameters of the system. Not used here.
Returns a list
containing the values of the two derivatives at .
example11
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.
# Plot the velocity field, nullclines and several trajectories example11_flowField <- flowField(example11, xlim = c(-5, 5), ylim = c(-5, 5), points = 21, add = FALSE) y0 <- matrix(c(4, 4, -1, -1, -2, 1, 1, -1), 4, 2, byrow = TRUE) example11_nullclines <- nullclines(example11, xlim = c(-5, 5), ylim = c(-5, 5), points = 200) example11_trajectory <- trajectory(example11, y0 = y0, tlim = c(0, 10)) # Determine the stability of the equilibrium points example11_stability_1 <- stability(example11, ystar = c(0, 0)) example11_stability_2 <- stability(example11, ystar = c(0, 2)) example11_stability_3 <- stability(example11, ystar = c(1, 1)) example11_stability_4 <- stability(example11, ystar = c(3, 0))
ode
Michael J Grayling