FreeBSD Manual Pages
elpa_set(3) Library Functions Manual elpa_set(3) NAME elpa_set - set a parameter for the ELPA object. SYNOPSIS FORTRAN INTERFACE use elpa class(elpa_t), pointer :: elpa_handle call elpa_handle%set (name, value, error) With the definitions of the input and output variables: class(elpa_t) :: elpa An instance of the ELPA object. character(*) :: name The name of the option to be set. datatype :: value the value which should be assigned to the option name. The datatype can be integer or real(kind=c_double). integer, optional :: error The returned error code. On success it is ELPA_OK, otherwise an er- ror. he error code can be queried with elpa_strerr(3) C/C++ INTERFACE #include <elpa/elpa.h> elpa_t elpa_handle; void elpa_set (elpa_t elpa_handle, const char *name, datatype value, int *error); With the definitions of the input and output variables: elpa_t elpa_handle; The handle of an ELPA object, obtained before with elpa_allocate(3) const char *name; The name of the option to be set. datatype value; The value which should be assigned to the option name. The datatype can be either int or double. int *error; The error code of the function. Should be "ELPA_OK". The error codes can be queried with elpa_strerr(3) DESCRIPTION The elpa_set function is used to set mandatory parameters and runtime op- tions of the ELPA library. It returns an error code which can be queried with elpa_strerr(3). Mandatory parameters: Mandatory parameters of an ELPA instance have to be set BEFORE the ELPA in- stance is set up with the function elpa_setup(3). At the moment the following mandatory parameters are supported: "na": integer parameter. The global matrix has size is (na * na) "nev": integer parameter. The number of eigenvectors to be computed in a call to elpa_eigenvectors(3). Must satisfy 1 <= nev <= na. "local_nrows": integer parameter. Number of matrix rows stored on this MPI process. "local_ncols": integer parameter. Number of matrix columns stored on this MPI process. "process_row": integer parameter. Process row number in the 2D domain decomposi- tion. "process_col": integer parameter. Process column number in the 2D domain decomposi- tion. "mpi_comm_parent": integer parameter. The parent MPI communicator which includes all MPI process which are used in the 2D domain decomposition. "bandwidth": integer parameter. Some ELPA computational steps can be accelerated if the input matrix is already in banded form. If set, ELPA assumes that the matrix has the provided bandwidth. "BLACS_context": integer parameter. The generalized eigenvalue solver elpa_general- ized_eigenvectors(3) uses internal calls to some of the ScaLAPACK routines. Thus before calling it, the user has to provide properly initialized BLACS context. "timings": integer parameter. Choose whether time measurements should be done in the ELPA routines (1) or not (0). Runtime options: Runtime options of an ELPA option can be set at any time. Here are some suuported runtime options: "solver": Choose which solver should be used in the compute steps elpa_eigen- values(3) or elpa_eigenvectors(3). At the moment allowed option are "ELPA_SOLVER_1STAGE" or "ELPA_SOLVER_2STAGE". "real_kernel": Choose which real kernel should be used in the elpa_eigenvalues(3) or elpa_eigenvectors(3) compute steps, if solver is set to "ELPA_SOLVER_2STAGE". The available kernels can be queried with elpa2_print_kernels(1). "complex_kernel": Choose which complex kernel should be used in the elpa_eigenval- ues(3) or elpa_eigenvectors(3) compute steps, if solver is set to "ELPA_SOLVER_2STAGE". The available kernels can be queried with elpa2_print_kernels(1). "qr": Choose whether a QR decomposition should be used for the real case computations in elpa_eigenvalues(3) or elpa_eigenvectors(3) computa- tional steps, if solver was set to "ELPA_SOLVER_2STAGE". "debug": Choose whether, in case of an error, more debug information should be provided. The full list of supported options can found in the ELPA documenta- tion. SEE ALSO elpa2_print_kernels(1) elpa_init(3) elpa_allocate(3) elpa_setup(3) elpa_strerr(3) elpa_eigenvalues(3) elpa_eigenvectors(3) elpa_cholesky(3) elpa_invert_triangular(3) elpa_solve_tridiagonal(3) elpa_hermitian_multi- ply(3) elpa_deallocate(3) elpa_uninit(3) ELPA Thu Nov 28 2024 elpa_set(3)
NAME | SYNOPSIS | DESCRIPTION | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=elpa_set&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>