%Main function

%Assign values to parameters
m=1;
c=0;
k=4;

%Give initial conditions
z0=[1; 0];

%Give the time interval to compute the solution
tspan=[0 100];

%Solve for the solution of the initial value problem using ode45 from
%Matlab
options=odeset('RelTol',1e-5,'AbsTol',1.e-5);
[t,z]=ode45('fcnspring',tspan,z0,options,m,c,k);

%Plot the solutions
figure(1)
plot(t,z(:,1),'b-*',t,z(:,2),'r-v')
grid on
xlabel('Time')
ylabel('Displacement and Velocity')
title('Spring-Mass-Dashpot System Solution')
legend('Displacement','Velocity',0)

%Plot the solution and the forcing function
figure(2)
forcing=sin(2*t);
plot(t,z(:,2),'b-*',t,forcing,'r-v')
grid on
xlabel('Time')
ylabel('Displacement and Forcing Function')