Clear Filters
Clear Filters

Why is the ODE solver saying not enough input arguments?

1 view (last 30 days)
In this program I am modeling the cell cycle with three differential equations. I am trying to output all three variables C, M and X to a graph, but I am missing something. Here's the code:
function Cellcycle= Cellcycle (~,~,~,~,~,~,~,~,~,~,~,~,~,~,~,~,~,~,~)
K1 = 0.005;
K2 = 0.005;
K3 = 0.005;
K4 = 0.005;
Kc = 0.5;
Kd = 0.02;
kd = 0.01;
V2 = 1.5;
V4 = 0.5;
vd = 0.25;
VM1 = 3;
VM3 = 1;
C = 0.01;
M = 0.01;
X = 0.01;
dC= 0.025-vd*X*(C/(Kd+C)) - kd*C;
dM = VM1*(C/(Kc+C))*((1-M)/(K1+(1-M))) - V2*(M/(K2+M));
dX = M*VM3*((1-X)/(K3+(1-X))) - V4*(X/(K4+X));
Cellcycle= [dC dM dX];
[~,~,~,~,~,~,~,~,~,~,~,~,~,~,~,~] = ode45('Cellcycle',ode45,[0 10],[.01 .01 .01]);
plot(dC,dM,dX);
end

Accepted Answer

Walter Roberson
Walter Roberson on 28 Feb 2016
Note that you are ignoring the ode inputs, so your calls are always going to return the same thing, with a rather boring output as a result. I have taken the liberty of guessing what you are trying to do and changing the code appropriately
function Cellcycle_driver
[t,y] = ode45(@Cellcycle, [0 10], [.01 .01 .01]);
dC = y(:,1);
dM = y(:,2);
dX = y(:,3);
plot(t, dC, 'g', t, dM, 'b', t, dX, 'r');
legend({'dC', 'dM', 'dX'});
function dy = Cellcycle(t, y)
K1 = 0.005;
K2 = 0.005;
K3 = 0.005;
K4 = 0.005;
Kc = 0.5;
Kd = 0.02;
kd = 0.01;
V2 = 1.5;
V4 = 0.5;
vd = 0.25;
VM1 = 3;
VM3 = 1;
% C = 0.01;
% M = 0.01;
% X = 0.01;
C = y(1):
M = y(2);
X = y(3);
dC= 0.025-vd*X*(C/(Kd+C)) - kd*C;
dM = VM1*(C/(Kc+C))*((1-M)/(K1+(1-M))) - V2*(M/(K2+M));
dX = M*VM3*((1-X)/(K3+(1-X))) - V4*(X/(K4+X));
dy = [dC; dM; dX];
  1 Comment
Mohannad Abboushi
Mohannad Abboushi on 28 Feb 2016
Edited: Mohannad Abboushi on 28 Feb 2016
I made into one function because it was giving some weird error message with cellcycle_driver. It's saying, "Not enough input arguments. Error in Cellcycle (line 17) C= y(1);"
function dy = Cellcycle(t, y)
K1 = 0.005;
K2 = 0.005;
K3 = 0.005;
K4 = 0.005;
Kc = 0.5;
Kd = 0.02;
kd = 0.01;
V2 = 1.5;
V4 = 0.5;
vd = 0.25;
VM1 = 3;
VM3 = 1;
% C = 0.01;
% M = 0.01;
% X = 0.01;
C = y(1);
M = y(2);
X = y(3);
%Differential equations%
dC= 0.025-vd*X*(C/(Kd+C)) - kd*C;
dM = VM1*(C/(Kc+C))*((1-M)/(K1+(1-M))) - V2*(M/(K2+M));
dX = M*VM3*((1-X)/(K3+(1-X))) - V4*(X/(K4+X));
dy = [dC; dM; dX];
%ODE Solver%
[t,y] = ode45(@Cellcycle, [0 10], [.01 .01 .01]);
dC = y(:,1);
dM = y(:,2);
dX = y(:,3);
plot(t, dC, 'g', t, dM, 'b', t, dX, 'r');
legend({'dC', 'dM', 'dX'});
end

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!