What's the problem that makes my MATLAB busy?

I am trying to graph 5 differential equations.

function dYfuncvecdt=ODEfunc(t, Yfuncvec)
  L= Yfuncvec(1);
  Cs= Yfuncvec(2);
  Ci= Yfuncvec(3);
  Rs= Yfuncvec(4);
  Ri= Yfuncvec(5);
  % Explicit equation
  kf = 7.2e7;
  kr = .34;
  kt = .03;
  ke = .165;
  kdeg = .0022;
  Vr = .013;
  Nav = 6.02*10^23;
  n = 10^9;
  % Differential equations
  dLdt = (-kf*L*Rs+kr*Cs)*(n/Nav);
  dCsdt = kf*L*Rs-(kr+ke)*Cs;
  dCidt = ke*Cs-kdeg*Ci;
  dRsdt = -kf*L*Rs+kr*Cs+Vr-kt*Rs;
  dRidt = kt*Rs-kdeg*Ri;
  dYfuncvecdt=[dLdt;dCsdt;dCidt;dRsdt;dRidt];

I have no problem until here. This code works. But when i want to graph it by

clear
clc
close all
tspan = [0 60]; % Range for the time of the reaction
y0 = [0.1;0;0;5*10^(4);0]; % Initial values for the dependent variables
[t y]=ode45(@ODEfunc,tspan,y0);
plot(t,y(:,1),t,y(:,2),t,y(:,3),t,y(:,4),t,y(:,5));
legend('L','Cs','Ci','Rs','Ri')
xlabel('Time(min)')
ylabel('(M)')

It never graphs. MATLAB is busy. When I stop it by CTRL+C, i get the error

??? Operation terminated by user during ==> ode45 at 481

Answer 1

[Arthur Goldsipe]

You interrupted ode45, the function that solves your ODEs. This means MATLAB was still busy integrating your ODEs.

It can take a very long time to solve a problem if you use the wrong solver for your problem. My guess is that you are trying to solve a "stiff" problem, and that you should use an ODE solver specifically designed for "stiff" problems, such as ode15s.