def mySolve(xf,boltz_eqs,rtol,atol,verbosity=50):
"""Sets the main options for the ODE solver and solve the equations. Returns the
array of x,y points for all components.
If numerical instabilities are found, re-do the problematic part of the evolution with smaller steps"""
boltz_solver = CVode(boltz_eqs) #Define solver method
boltz_solver.rtol = rtol
boltz_solver.atol = atol
boltz_solver.verbosity = verbosity
boltz_solver.linear_solver = 'SPGMR'
boltz_solver.maxh = xf/300.
xfinal = xf
xres = []
yres = []
sw = boltz_solver.sw[:]
while xfinal <= xf:
try:
boltz_solver.re_init(boltz_eqs.t0,boltz_eqs.y0)
boltz_solver.sw = sw[:]
x,y = boltz_solver.simulate(xfinal)
xres += x
for ypt in y: yres.append(ypt)
if xfinal == xf: break #Evolution has been performed until xf -> exit
except Exception,e:
print e
if not e.t or 'first call' in e.msg[e.value]:
logger.error("Error solving equations:\n "+str(e))
return False
xfinal = max(e.t*random.uniform(0.85,0.95),boltz_eqs.t0+boltz_solver.maxh) #Try again, but now only until the error
logger.warning("Numerical instability found. Restarting evolution from x = "
+str(boltz_eqs.t0)+" to x = "+str(xfinal))
continue
xfinal = xf #In the next step try to evolve from xfinal -> xf
sw = boltz_solver.sw[:]
x0 = float(x[-1])
y0 = [float(yval) for yval in y[-1]]
boltz_eqs.updateValues(x0,y0,sw)
