preCICE Initialization error

[mishal49]

Hello
I was trying to couple an IB code with preCICE and added the following code:

#include “precice/SolverInterface.hpp”

int rank = 0;
int size = 1;
precice::SolverInterface precice(“FluidSolver”,“precice-config.xml”,rank,size);

double dt; // solver timestep size
double precice_dt; // maximum precice timestep size

precice_dt = precice.initialize();

However, it gives an initialization error:

/opt/apps/gcc/9.4.0/bin/ld: IBFoam.C:(.text+0x30b6): undefined reference to precice::SolverInterface::initialize()' /opt/apps/gcc/9.4.0/bin/ld: IBFoam.C:(.text+0x5fb8): undefined reference to precice::SolverInterface::~SolverInterface()’
/opt/apps/gcc/9.4.0/bin/ld: IBFoam.C:(.text+0x9306): undefined reference to `precice::SolverInterface::~SolverInterface()’
make: *** [/work/07083/kk0551/OpenFOAM/OpenFOAM-v2112/wmake/makefiles/general:150: /work/07083/kk0551/OpenFOAM/OpenFOAM-v2112/platforms/linux64IccDPInt64Opt/bin/ibFoam] Error 1

Could someone please elaborate on the meaning of rank and size and the reason for the generation of this error?

Would appreciate any help

[Makis]

The error you are getting is:

undefined reference to precice::SolverInterface::initialize()

this is originating from the linker: /opt/apps/gcc/9.4.0/bin/ld

Most probably, this means that you have not linked to preCICE when building your code. Usually, one needs to provide a -lprecice flag to the compiler/Makefile (together with a -L/path/to/precice).

@mishal49

Could someone please elaborate on the meaning of rank and size

These have to do with parallel simulations. rank is “which process am I?” and size is “how many processes are we, in total?”. 0 and 1 are the values you need for serial simulations.