Overview#

The C++ library is the foundation that all other language bindings are built on, and gives direct access to MICM, TUV-x, and CARMA. For installation, see C++.

Defining a Mechanism#

Mechanisms are loaded from a mechanism configuration file directory. Use the bundled configs/v0/analytical example or provide your own:

#include <musica/micm.hpp>

auto micm = musica::MICM("configs/v0/analytical",
                          musica::MICMSolver::RosenbrockStandardOrder);

See CMake Configuration Options for build options including TUV-x, CARMA, and GPU support.

Creating a Solver#

The solver type is selected at construction time. Available options in musica::MICMSolver:

Solver	Description
`RosenbrockStandardOrder`	Rosenbrock solver (standard species ordering)
`RosenbrockArbitraryOrder`	Rosenbrock solver (arbitrary species ordering)
`BackwardEulerStandardOrder`	Backward Euler solver (standard species ordering)
`BackwardEulerArbitraryOrder`	Backward Euler solver (arbitrary species ordering)
`CudaRosenbrock`	GPU Rosenbrock solver (requires CUDA build)

Setting Conditions#

Create a state and set concentrations and environmental conditions:

auto state = micm.CreateState();

state.SetConcentrations({ {"A", {1.0}}, {"B", {3.0}}, {"C", {5.0}} });
state.SetConditions(300.0 /*K*/, 101000.0 /*Pa*/);

Solving#

Call Solve at each time step:

double time_step  = 4.0;   // s
double sim_length = 20.0;  // s

for (double t = time_step; t <= sim_length; t += time_step) {
  micm.Solve(state, time_step);
}

Accessing Results#

Retrieve updated concentrations from the state after each solve:

auto conc = state.GetConcentrations();
std::cout << "t=" << t << "s  A=" << conc["A"][0] << "\n";

Using MUSICA in a CMake Project#

Link MUSICA into your project with find_package:

find_package(musica REQUIRED)
target_link_libraries(my_target musica::musica)

If installed to a non-standard prefix:

cmake -D CMAKE_PREFIX_PATH=<INSTALL_DIR> ..