print "DYNAMIC CHARACTERISTICS OF A RATTRAP"
sk=input("Enter spring const, in lb-ft/rad [try 0.669]: ")
ai=input("Enter moment of intertia, in lb-ft-sec**2 [try 0.0006]: ")
torcl=input("Enter torque in closed position, in lb-ft [try 0.625]: ")
thcl=input("Enter jaw angle in closed position, in radians [try 3.270]: ")
delt=input("Enter time increment, in sec [try 0.0001]: ")
dtpr=input("Enter print increment, in sec [try 0.001]: ")
epsi=input("Enter convergence criterion [try 0.00003]: ")
t=th=thd=0.
tpr=dtpr
dtest=thcl-th
while dtest > 0:
    thddt=(torcl+sk*thcl)/ai -sk*th/ai
    thd1=thd+thddt*delt
    th+=(thd+thd1)*delt/2.
    thd=thd1
    t+=delt
    dtest=thcl-th
    if(abs(t-tpr) <= epsi):
        print t,th,thd
        tpr+=dtpr