Category Archives: Coding

odeint speaks OpenCL

In the previous post I wrote some words about VexCL, a library for OpenCL. This library can easily be used within odeint. I only needed to create an adapter for the odeint resizing mechanism and then it was done. VexCL supports expression template and therefore, it can be used with odeints vector_space_algebra and default_operations. Continue reading

VexCL – High-level OpenCL

Some days ago I found a very nice library for building OpenCL applications: VexCL. It is really high level such that you must not care about things like memory management. It uses expression templates, such that you can write very compact and readable code. It is also possible to use VexCL with odeint, I will show in the next days some examples here.

C++Now!

Mario Mulansky and me will visit this years C++Now! conference formerly known as BoostCon, held on May 13-18, 2012, in Aspen Colorado. It is one of the largest conferences devoted to C++ and we will present an overview talk on odeint. Furthermore, we will introduce some techniques used in odeint. We would be happy to meet and discuss with anyone who has interest in odeint there, of course.

Using Boost Build

I use bjam and Boost.Build since a while and they are really great. You can easily use them to build multi-platform applications and they automatically resolve the C++ header dependencies, which is difficult to realize with make and makefiles. Writing Jamfiles is in principle easy, but in the beginning it is hard to figure out how it works, especially if you are following the official documentation. Today, I found an easy way to link the boost libraries and how easy the boost headers can be included: Continue reading

Advanced expression tree manipulations

I have created a github project for the Taylor series method of ordinary differential equations. It is an addon to odeint and will be one day a part of it.

The Taylor series methods determines the solution of an ODE by its Taylor coefficients. The theory is extremely simple but the difficulty is to determine these coefficients numerically and in an unique way. To do so automatic differentiation is used where the formulas defining the ODE are given as expression trees and are then sequentially evaluated to obtain the n-the derivative or the n-th Taylor coefficient. Continue reading

Numerical algorithms and template meta programmiming

Here is an article about template-meta-programming and numerical algorithms. It illustrates how one can construct an numerical algorithm during compile-time. The example for this technique is the family of explicit Runge-Kutta solvers for ordinary differential equation.

www.c-plusplus.de/forum/282091

Sorry, it is only in German.

Run-time performance of expression trees

A few days ago, I played around with proto, a C++ library the for construction and evaluation of expression trees. I wanted to write a small application allowing me to write classical vector operations in a neat way like b+2*c+d*e. With proto this is possible with only a few lines of code. Surprisingly, it turned out that the run-time performance for large expressions was about 10 to 20 percent better than a naive implementation. Continue reading