VFGEN § ADOL-C

ADOL-C

ADOL-C implements automatic differentiation in C++.

The VFGEN ADOL-C Command

C++ files that can be used with ADOL-C are created by the command

$ vfgen adolc vector_field_file.vf

The files created are [name]_adolc.cpp and [name]_adolc.h, where [name] is the name of the vector field given in the vector field file. The C++ file [name]_adolc.cpp will contain the function

[name]_vf(short int tag, double *y_, double *f_, double *params_)

Example

Here is a sample vector field file: pendulum.vf.
The files created by

$ vfgen adolc pendulum.vf

are

As an example of how the pendulum_vf() function might be used, the program pend_solver.cpp implements a simple ODE solver with a fixed step size. A Makefile for this program is Makefile-pend_solver. The program can be compiled with the command

$ make -f Makefile-pend_solver

If ADOL-C is installed in a nonstandard directory, say, /opt/adolc, the following command can be used:

$ make CPPFLAGS=-I/opt/adolc/include LDFLAGS=-L/opt/adolc/lib -f Makefile-pend_solver

This will create the executable program called pend_solver, which can be run as follows:

$ ./pend_solver > pend7.dat

The following is a plot of the solution generated by pend_solver: