6.11.2. statsmodels.sandbox.tsa.diffusion

getting started with diffusions, continuous time stochastic processes

Author: josef-pktd License: BSD

6.11.2.1. References

An Algorithmic Introduction to Numerical Simulation of Stochastic Differential Equations Author(s): Desmond J. Higham Source: SIAM Review, Vol. 43, No. 3 (Sep., 2001), pp. 525-546 Published by: Society for Industrial and Applied Mathematics Stable URL: http://www.jstor.org/stable/3649798

http://www.sitmo.com/ especially the formula collection

6.11.2.2. Notes

OU process: use same trick for ARMA with constant (non-zero mean) and drift some of the processes have easy multivariate extensions

Open Issues

include xzero in returned sample or not? currently not

TODOS

  • Milstein from Higham paper, for which processes does it apply
  • Maximum Likelihood estimation
  • more statistical properties (useful for tests)
  • helper functions for display and MonteCarlo summaries (also for testing/checking)
  • more processes for the menagerie (e.g. from empirical papers)
  • characteristic functions
  • transformations, non-linear e.g. log
  • special estimators, e.g. Ait Sahalia, empirical characteristic functions
  • fft examples
  • check naming of methods, “simulate”, “sample”, “simexact”, ... ?

stochastic volatility models: estimation unclear

finance applications ? option pricing, interest rate models

6.11.2.3. Classes

AffineDiffusion() differential equation:
ArithmeticBrownian(xzero, mu, sigma) :math:
BrownianBridge()
CompoundPoisson(lambd[, randfn]) nobs iid compound poisson distributions, not a process in time
Diffusion() Wiener Process, Brownian Motion with mu=0 and sigma=1
ExactDiffusion() Diffusion that has an exact integral representation
GeometricBrownian(xzero, mu, sigma) Geometric Brownian Motion
OUprocess(xzero, mu, lambd, sigma) Ornstein-Uhlenbeck
SchwartzOne(xzero, mu, kappa, sigma) the Schwartz type 1 stochastic process