# Turing instability   ch6-turing.ode 
# See Chapters 6.3.2 and 8.6.1 in our textbook for information about the Turing instability.

x1'=sigma*x1^2/(1+y1)-x1
y1'=rho*(x1^2-y1)+D*(y2-y1)
x2'=sigma*x2^2/(1+y2)-x2
y2'=rho*(x2^2-y2)+D*(y1-y2)


# Set the default values of the parameters:
# Don't put spaces between the parameter name, the equal sign, and the parameter value!
par D=0.1,rho=2.5,sigma=2.5

# Set the default initial conditions:
init x1=1.5  y1=4  x2=2  y2=4

# Set the default axes to project the solution trajectory onto the x2 versus x1 plane: 
@ xplot=x1, yplot=x2

# Set the default stopping time and time step
@ total=20, dt=0.01

# Set the default viewing window
@ xlo=0.0,xhi=3,ylo=0.0,yhi=3
done