Hi there,

I have a set of differential equations whose solution, Jacobian matrix and its eigenvalues, direction field, phase portrait and nullclines, need to be computed.

Each of the equations has a varying parameter.

I know how to get the above for a single parameter value, but when I set a range of values for the parameters, Maple is not able to handle all cases as I would expect: solving the differential equation system:

*eq1 := x*(1.6*(1-(1/100)*x)-phi*y)*

*eq2 := (x/(15+x)-0.3e-1*x-.4)*y+.6+theta*

*desys := [eq1, eq2];*

*vars := [x, y];*

**steadyStates := map2(eval, vars, [solve(desys)])**

already yields an error:

*Error, (in unknown) invalid input: Utilities:-SetEquations expects its 2nd argument, equations, to be of type set({boolean, algebraic, relation}), but received {-600*y+(Array(1..2, {(1) = 8400, (2) = 15900})), Array(1..5, {(1) = 0, (2) = 0, (3) = 0, (4) = 0, (5) = 0})}*

The equations are the following:

**de1 := diff(x(t), t) = x(t)*(1.6*(1-(1/100)*x(t))-phi*y(t)); **

**de2 := diff(y(t), t) = (x(t)/(15+x(t))-0.3e-1*x(t)-.4)*y(t)+.6+theta**

the parameters being:

**phi:=[0 0.5 1 1.5 2]**

**theta:=[5. 10.]**

How can I handle the situation so that Maple computes each of the above for each combination of the parameters?

I would like to avoid using two for loops and having to store all results in increasingly bigger and complicated arrays.

The worksheet at issue is this: MaplePrimes_Tumour_model_phi_theta_variation.mw

Thanks,

jon