This C/C++ code is an accompaniment to the paper: A Transport Equation Approach to Calculations of Hadamard Green Functions and off-diagonal DeWitt Coefficients. It numerically calculates the function appearing in the Hadamard form of the Green function for the wave equation in curved spacetime. Please see the paper for a full description.
There are two versions of the code available: a C version and a newer C++ version. It is provided as free software under the terms of the GNU General Public License version 2 (or later). If you find this code useful, please cite Phys. Rev. D 84, 104039 (2011).