elpa_solve_evp_real_2stage_double.3 5.86 KB
 Andreas Marek committed Nov 25, 2016 1 ``````.TH "elpa_solve_evp_real_2stage_double" 3 "Tue Oct 18 2016" "ELPA" \" -*- nroff -*- `````` Andreas Marek committed Nov 11, 2016 2 3 4 ``````.ad l .nh .SH NAME `````` Andreas Marek committed Nov 25, 2016 5 ``````elpa_solve_evp_real_2stage_double \- solve the double-precision real eigenvalue problem with the 2-stage ELPA solver `````` Andreas Marek committed Nov 11, 2016 6 7 8 9 10 11 12 13 14 ``````.br .SH SYNOPSIS .br .SS FORTRAN INTERFACE use elpa1 use elpa2 .br .br `````` Andreas Marek committed Nov 25, 2016 15 ``````.RI "success = \fBelpa_solve_evp_real_2stage_double\fP (na, nev, a(lda,matrixCols), ev(nev), q(ldq, matrixCols), ldq, nblk, matrixCols, mpi_comm_rows, mpi_comm_cols, mpi_comm_all, THIS_REAL_ELPA_KERNEL, useQR, useGPU)" `````` Andreas Marek committed Nov 11, 2016 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 ``````.br .RI " " .br .RI "With the definintions of the input and output variables:" .br .RI "integer, intent(in) \fBna\fP: global dimension of quadratic matrix \fBa\fP to solve" .br .RI "integer, intent(in) \fBnev\fP: number of eigenvalues to be computed; the first \fBnev\fP eigenvalules are calculated" .br .RI "real*8, intent(inout) \fBa\fP: locally distributed part of the matrix \fBa\fP. The local dimensions are \fBlda\fP x \fBmatrixCols\fP" .br .RI "integer, intent(in) \fBlda\fP: leading dimension of locally distributed matrix \fBa\fP" .br .RI "real*8, intent(inout) \fBev\fP: on output the first \fBnev\fP computed eigenvalues" .br .RI "real*8, intent(inout) \fBq\fP: on output the first \fBnev\fP computed eigenvectors" .br .RI "integer, intent(in) \fBldq\fP: leading dimension of matrix \fBq\fP which stores the eigenvectors" .br .RI "integer, intent(in) \fBnblk\fP: blocksize of block cyclic distributin, must be the same in both directions" .br .RI "integer, intent(in) \fBmatrixCols\fP: number of columns of locally distributed matrices \fBa\fP and \fBq\fP" .br .RI "integer, intent(in) \fBmpi_comm_rows\fP: communicator for communication in rows. Constructed with \fBelpa_get_communicators\fP(3)" .br .RI "integer, intent(in) \fBmpi_comm_cols\fP: communicator for communication in colums. Constructed with \fBelpa_get_communicators\fP(3)" .br .RI "integer, intent(in) \fBmpi_comm_all\fP: communicator for all processes in the processor set involved in ELPA" .br .RI "integer, intent(in), optional \fBTHIS_ELPA_REAL_KERNEL\fp: choose the compute kernel for 2-stage solver" .br .RI "logical, intent(in), optional: \fBuseQR\fP: optional argument; switches to QR-decomposition if set to .true." `````` Andreas Marek committed Nov 25, 2016 49 50 51 ``````.br .RI "logical, intent(in), optional: \fBuseGPU\fP: decide whether GPUs should be used or not" .br `````` Andreas Marek committed Nov 11, 2016 52 53 54 55 56 57 ``````.RI "logical \fBsuccess\fP: return value indicating success or failure" .br .SS C INTERFACE #include "elpa.h" .br `````` Andreas Marek committed Nov 25, 2016 58 ``````.RI "success = \fBelpa_solve_evp_real_2stage_double\fP (\fBint\fP na, \fBint\fP nev, \fB double *\fPa, \fBint\fP lda, \fB double *\fPev, \fBdouble *\fPq, \fBint\fP ldq, \fBint\fP nblk, \fBint\fP matrixCols, \fBint\fP mpi_comm_rows, \fBint\fP mpi_comm_cols, \fBint\fP mpi_comm_all, \fBint\fP THIS_ELPA_REAL_KERNEL, \fBint\fP useQR, \fBint\fP useGPU);" `````` Andreas Marek committed Nov 11, 2016 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 ``````.br .RI " " .br .RI "With the definintions of the input and output variables:" .br .RI "int \fBna\fP: global dimension of quadratic matrix \fBa\fP to solve" .br .RI "int \fBnev\fP: number of eigenvalues to be computed; the first \fBnev\fP eigenvalules are calculated" .br .RI "double *\fBa\fP: pointer to locally distributed part of the matrix \fBa\fP. The local dimensions are \fBlda\fP x \fBmatrixCols\fP" .br .RI "int \fBlda\fP: leading dimension of locally distributed matrix \fBa\fP" .br .RI "double *\fBev\fP: pointer to memory containing on output the first \fBnev\fP computed eigenvalues" .br .RI "double *\fBq\fP: pointer to memory containing on output the first \fBnev\fP computed eigenvectors" .br .RI "int \fBldq\fP: leading dimension of matrix \fBq\fP which stores the eigenvectors" .br .RI "int \fBnblk\fP: blocksize of block cyclic distributin, must be the same in both directions" .br .RI "int \fBmatrixCols\fP: number of columns of locally distributed matrices \fBa\fP and \fBq\fP" .br .RI "int \fBmpi_comm_rows\fP: communicator for communication in rows. Constructed with \fBelpa_get_communicators\fP(3)" .br .RI "int \fBmpi_comm_cols\fP: communicator for communication in colums. Constructed with \fBelpa_get_communicators\fP(3)" .br .RI "int \fBmpi_comm_all\fP: communicator for all processes in the processor set involved in ELPA" .br .RI "int \fBTHIS_ELPA_REAL_KERNEL\fp: choose the compute kernel for 2-stage solver" .br .RI "int \fBuseQR\fP: if set to 1 switch to QR-decomposition" `````` Andreas Marek committed Nov 25, 2016 92 93 94 ``````.br .RI "int \fBuseGPU\fP: decide whether GPUs should be used or not" .br `````` Andreas Marek committed Nov 11, 2016 95 96 97 98 99 100 101 102 ``````.RI "int \fBsuccess\fP: return value indicating success (1) or failure (0) .SH DESCRIPTION Solve the real eigenvalue problem with the 2-stage solver. The ELPA communicators \fBmpi_comm_rows\fP and \fBmpi_comm_cols\fP are obtained with the \fBelpa_get_communicators\fP(3) function. The distributed quadratic marix \fBa\fP has global dimensions \fBna\fP x \fBna\fP, and a local size \fBlda\fP x \fBmatrixCols\fP. The solver will compute the first \fBnev\fP eigenvalues, which will be stored on exit in \fBev\fP. The eigenvectors corresponding to the eigenvalues will be stored in \fBq\fP. All memory of the arguments must be allocated outside the call to the solver. .br The interface \fBelpa_solve_evp_real\fP(3) is a more flexible alternative. .br .SH "SEE ALSO" `````` Andreas Marek committed Nov 25, 2016 103 ``\fBelpa_get_communicators\fP(3) \fBelpa_solve_evp_real\fP(3) \fBelpa_solve_evp_complex\fP(3) \fBelpa_solve_evp_real_1stage\fP(3) \fBelpa_solve_evp_complex_1stage\fP(3) \fBelpa_solve_evp_real_2stage_single\fP(3) \fBelpa_solve_evp_complex_2stage_double\fP(3) \fBelpa_solve_evp_complex_2stage_singe\fP(3) \fBelpa2_print_kernels\fP(1)``