how to pass varibles to the function while using ODE45

hi
can someone tell me how to remove the variables in the function mentioned and include it in the arguments
function code
function out = pvar(ct,vector)
k =1.32;
Vd = 2;
r = 8.1;
R = 5.5;
P = vector(1);
W = vector(2);
Vc = Vd/(r-1);
V = Vc*(1+0.5*(r-1)*(R+1-cosd(ct)-((R^2)-((sind(ct))^2))^0.5));
dV = Vc*(r/2 - 1/2)*((pi*sin((pi*ct)/180))/180 + (pi*cos((pi*ct)/180)*sin((pi*ct)/180))/(180*(R^2 - sin((ct*pi)/180)^2)^(1/2)));
dPdt = -k*P*dV/V;
dWdt = P*dV;
out = [dPdt;dWdt;dV];
end
script
k =1.32;
Vd = 2;
r = 8.1;
R = 5.5;
IC = [112,0,Vc+Vd];
theta = [-180,0];
[ct,sol] = ode45(@pvar,theta,IC);

 Accepted Answer

1 Comment

k =1.32;
Vd = 2;
r = 8.1;
R = 5.5;
Vc = Vd/(r-1);
IC = [112,0,Vc+Vd];
theta = [-180,0];
[ct,sol] = ode45(@(ct,vector)pvar(ct,vector,k,Vd,r,R,Vc),theta,IC);
figure(1)
plot(ct,sol(:,1));
title('Pressure vs. Crank Angle')
xlabel('Crank Angle (deg)')
ylabel('Pressure (kPa)')
grid
figure(2)
plot(ct,sol(:,2));
title('Work vs. Crank Angle')
xlabel('Crank Angle (deg)')
ylabel('Work (kJ)')
grid
figure(3)
plot(sol(:,3),sol(:,1))
title('Pressure vs. Volume')
xlabel('Volume (l)')
ylabel('Presure (kPa)')
grid
function out = pvar(ct,vector,k,Vd,Vc,r,R)
P = vector(1);
W = vector(2);
V = Vc*(1+0.5*(r-1)*(R+1-cosd(ct)-((R^2)-((sind(ct))^2))^0.5));
dV = Vc*(r/2 - 1/2)*((pi*sin((pi*ct)/180))/180 + (pi*cos((pi*ct)/180)*sin((pi*ct)/180))/(180*(R^2 - sin((ct*pi)/180)^2)^(1/2)));
dPdt = -k*P*dV/V;
dWdt = P*dV;
out = [dPdt;dWdt;dV];
end

Sign in to comment.

More Answers (0)

Asked:

on 24 Feb 2019

Commented:

on 24 Feb 2019

Community Treasure Hunt

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

Start Hunting!