if var in options:
options[var] = float(val)
else:
print 'Unknown argument: ', a
use()
sys.exit()
# Get the values for the initial conditions and parameters from the options dict.
y_ = []
for i in range(N_):
y_ = y_ + [options[varnames_[i]]]
p_ = []
for i in range(P_):
p_ = p_ + [options[parnames_[i]]]
# Create the time samples for the output of the ODE solver.
tfinal = options['stoptime']
N = int(options['numpoints'])
if N < 2:
print 'The number of points must be at least 2.'
sys.exit()
t = [tfinal*float(i)/(N-1) for i in range(N)]
# Call the ODE solver.
ysol = odeint(pendulum.vectorfield,y_,t,args=(p_,),Dfun=pendulum.jacobian,atol=options['abserr'],rtol=options['relerr'])
# Print the solution.
for t1,y1 in zip(t,ysol):
print t1,y1[0],y1[1],
print pendulum.energy(y1,t1,p_)