Friday, July 17, 2009
- 830 –900 Registration
- 900 –915 Welcome
- 915 –945 Talk
- Hans Skaug (University of Bergen)
The AD Model Builder project
AD Model Builder (ADMB) is a powerful programming package that uses
automatic differention for the development and fitting of statistical
models to data. It contains a suite of techniques (e.g. powerful
function minimizer, profile likelihoods, MCMC simulation, random effects
modelling) which makes it a unique framework for working with
highly parameterized nonlinear models. ADMB was originally developed by David Fournier and is
now an open source project ( http://admb-project.org/). It has found
application in numerous practical natural resource assessment and
management projects has been used in hundreds of scientific papers. In
this talk we will briefly introduce the internal working of ADMB as the
development of user applications. We also describe the open source
project, the goal of which is to maintain and further develop AD Model
Builder.
- 945 –1015 Talk
- Finlay Scott (CEFAS)
AD in R
R is a powerful, flexible and open source software environment for statistical computing and graphics. It is widely used throughout the scientific community and its popularity is growing. One of R's key advantages is that it is highly extensible. There are currently about 2000 user-developed packages publicly available that expand the core
functionality. It is also possible to link R to other languages, including C/C++ and Fortran, to speed up computationally intensive processes. Although R includes general purpose optimisation routines based on numerical approximation and also some basic symbolic differentiation, R does not currently include Automatic Differentiation (AD) capabilities. We have linked R to open-source AD libraries such as ADOL-C and Autodiff to develop fisheries models, demonstrating the value of using AD within R. However, this approach has focused on specific applications and there is currently no generic AD interface for R. Here we present a general overview of the R language and highlight the importance of developing such a generic, useable AD interface for R. We are interested in collaborating with
the AD community to help us achieve this goal.
- 1015 –1045 Talk
- Sebastian Walter (HU Berlin)
AD in Python with Application in Science and Engineering
Python becomes more and more popular as a general purpose programming language, also in
science and engineering. In this talk we show a few examples of scientific programs that require
derivative information. One example will be the optimization of an NLP with PYIPOPT. We
use the examples to illustrate how to differentiate those programs with PyCPPAD, PyADOLC
and ALGOPY from the user's perspective. We also discuss the execution speed of PyADOLC
and ALGOPY with pure C++ ADOL-C and briefly explain how the interface between Python
and C++ is implemented with Boost::Python.
- 1045 –1115 Coffee
- 1115 –1145 Talk
- Laurent Hascoet (INRIA Sophia-Antipolis, France)
Tapenade as a front-end for ADOL-C
Our team is designing a special mode of Tapenade that
makes it a preprocessor for ADOL-C. After Tapenade data-flow and activity analysis, we generate
source for ADOL-C with selected variable types
changed to "aDouble". We shall discuss some issues
raised by this development.
- 1145 –1215 Talk
- Jean Utke (Argonne National Laboratory)
Rapsodia
- 1215 –1345 Lunch
- 1345 –1415 Talk
- Paul Hovland (Argonne National Laboratory)
TBD
TBD
- 1415 –1445 Talk
- Viktor Mosenkis (RWTH Aachen)
On integer stack compression in adjoint codes
- 1445 –1515 Coffee
- 1515 –1600 Talk
- Jeremy Walton (NAG Ltd.)
NAG and Automatic Differentiation
- 1600 –1700 Open Discussion and Closing Remarks
- 1700 The End
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