Polyfem as Libary¶

Polyfem uses modern cmake, so it it should be enough to add this line

add_subdirectory(<path-to-polyfem> polyfem)

in your cmake project, and then simply add

target_link_library(<your_target> polyfem)

in your cmake script. Polyfem will download the dependencies that it needs with the version that it needs. If you dont need the viewer for your own project you can add

SET(POLYFEM_NO_UI ON)

Interface¶

The interface of polyfem is similar as Python. You should create a polyfem::State object and then call methods on it. Most of the fields are public for convenience but we discourage use or access them.

This is the main interface of polyfem::State.

Initialization¶

void init(const json &args)
void init(const std::string &json_path)

loads the settings from a json object or file

Logging¶

void set_log_level(int log_level)
std::string get_log()

Sets the log level (1-6) and gets the log at the end

Loading mesh¶

void load_mesh()
void load_mesh(const std::string &path)
void load_mesh(const Eigen::MatrixXd &V, const Eigen::MatrixXi &F)

Different ways of loading a mesh

Set boundary sides sets¶

void set_boundary_side_set(const std::function<int(const polyfem::RowVectorNd&)> &boundary_marker)
void set_boundary_side_set(const std::function<int(const polyfem::RowVectorNd&, bool)> &boundary_marker)
void set_boundary_side_set(const std::function<int(const std::vector<int>&, bool)> &boundary_marker)

All boundary side sets are assigned with a lambda function, the first 2 takes the barycenter of the face/edge, the last one the primite id. The second argument is a boolean that specifies if the sideset is boundary.

Solving¶

void solve();

Note the solver internally calls

void build_basis();
void assemble_stiffness_mat();
void assemble_rhs();
void solve_problem();

You can use these instead of solve.

If you problem has a solution you can use

void compute_errors();

to obtain the error.

Getters¶

const Eigen::MatrixXd &get_solution() const
const Eigen::MatrixXd &get_pressure() const

Gets the raw solution and pressure. The order of the coefficient is unrelated to the order of the vertices of the mesh.

void get_sampled_solution(Eigen::MatrixXd &points, Eigen::MatrixXi &tets, Eigen::MatrixXd &fun, bool boundary_only = false)
void get_stresses(Eigen::MatrixXd &fun, bool boundary_only = false)
void get_sampled_mises(Eigen::MatrixXd &fun, bool boundary_only = false)
void get_sampled_mises_avg(Eigen::MatrixXd &fun, Eigen::MatrixXd &tfun, bool boundary_only = false)

Gets the solution/stresses on the visualization mesh, use vismesh_rel_area to control density

Exporting¶

Exports the solution to VTU for visualization

void get_sidesets(Eigen::MatrixXd &pts, Eigen::MatrixXi &faces, Eigen::MatrixXd &sidesets);

void export_data();

void save_vtu(const std::string &name);
void save_wire(const std::string &name, bool isolines = false);

Last update: 2023-10-03