1.0 is running accumulator value and 0 is past fixings. It means that
only the reaming fixings are for averaging. There is something isn't perfectly right in floating strike engine implementation. These are the steps to reproduce "the bug". 1. Set dividend yield to zero. QL and my implementation perfectly agree. 2. Increase risk free rate and dividend yield by the same amount. This won't affect GBM dynamics. If we compensate for the higher discount factor then the prices shouldn't chance. Indeed, my implementation gives the same result, but QL gives slightly higher values. The difference is negligible (only 4th digits differ) for practical purposes, but it indicates that something isn't right, because floating strike analytical engine uses exact formula, not approximation When dividend yield is zero my implementation perfectly agrees with QL. Fixed strike prices agree in both cases (the difference only in 14th digit). ------------------------------------------------------------------------------ The modern datacenter depends on network connectivity to access resources and provide services. The best practices for maximizing a physical server's connectivity to a physical network are well understood - see how these rules translate into the virtual world? http://p.sf.net/sfu/oracle-sfdevnlfb _______________________________________________ QuantLib-dev mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/quantlib-dev |
Kakhkhor, sorry I didn't have time to look at the problem. Do you mind adding the issue to the bug tracker so it doesn't get lost? Thanks, Luigi On Mon, 2011-02-07 at 08:53 -0500, Kakhkhor Abdijalilov wrote: > 1.0 is running accumulator value and 0 is past fixings. It means that > only the reaming fixings are for averaging. > > There is something isn't perfectly right in floating strike engine > implementation. > > These are the steps to reproduce "the bug". > > 1. Set dividend yield to zero. QL and my implementation perfectly agree. > > 2. Increase risk free rate and dividend yield by the same amount. This > won't affect GBM dynamics. If we compensate for the higher discount > factor then the prices shouldn't chance. Indeed, my implementation > gives the same result, but QL gives slightly higher values. The > difference is negligible (only 4th digits differ) for practical > purposes, but it indicates that something isn't right, because > floating strike analytical engine uses exact formula, not > approximation > > When dividend yield is zero my implementation perfectly agrees with QL. > > Fixed strike prices agree in both cases (the difference only in 14th digit). > > ------------------------------------------------------------------------------ > The modern datacenter depends on network connectivity to access resources > and provide services. The best practices for maximizing a physical server's > connectivity to a physical network are well understood - see how these > rules translate into the virtual world? > http://p.sf.net/sfu/oracle-sfdevnlfb > _______________________________________________ > QuantLib-dev mailing list > [hidden email] > https://lists.sourceforge.net/lists/listinfo/quantlib-dev -- Vin: It's like this fellow I knew in El Paso. One day, he just took all his clothes off and jumped in a mess of cactus. I asked him that same question, "Why?" Calvera: And? Vin: He said, "It seemed like a good idea at the time." -- The Magnificent Seven ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ QuantLib-dev mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/quantlib-dev |
I am planning to submit my own implementation to QL. Bug report will follow.
Regards, Kakhkhor Abdijalilov. ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ QuantLib-dev mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/quantlib-dev |
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