Is there a way to reduce oscillations for the numerical integration when evaluating the Heston model. I am pricing a series of 5000 options scattered over the Heston model parameter space and I find that for some parameters, often deep-out-of-the-money options I get negative option prices. I am using 32 Gauss-Laguerre integration, so the integration grid is rather fine, also I have tried extending the maturities to say 10 years, but this only reduces the frequency.
If not I guess Monte-Carlo is the only way to make sure I get no negative prices.
Thanks Sam