TY - JOUR A1 - Gutheil, Inge A1 - Berg, Tommy A1 - Grotendorst, Johannes T1 - Performance Analysis of Parallel Eigensolvers of two Libraries on BlueGene/P JF - Journal of Mathematics and Systems Science N2 - Many applications in computational science and engineering require the computation of eigenvalues and vectors of dense symmetric or Hermitian matrices. For example, in DFT (density functional theory) calculations on modern supercomputers 10% to 30% of the eigenvalues and eigenvectors of huge dense matrices have to be calculated. Therefore, performance and parallel scaling of the used eigensolvers is of upmost interest. In this article different routines of the linear algebra packages ScaLAPACK and Elemental for parallel solution of the symmetric eigenvalue problem are compared concerning their performance on the BlueGene/P supercomputer. Parameters for performance optimization are adjusted for the different data distribution methods used in the two libraries. It is found that for all test cases the new library Elemental which uses a two-dimensional element by element distribution of the matrices to the processors shows better performance than the old ScaLAPACK library which uses a block-cyclic distribution. KW - performance analysis KW - Elemental KW - ScaLAPACK KW - eigensolvers KW - Numerical linear algebra Y1 - 2012 U6 - http://dx.doi.org/10.17265/2159-5291/2012.04.003 SN - 2159-5291 VL - 2 IS - 4 SP - 231 EP - 236 PB - David Publishing CY - Libertyville ER - TY - JOUR A1 - Grotendorst, Johannes T1 - Supercomputer programmieren - ein besonderes Studienangebot in Jülich JF - Junge Wissenschaft. 27 (2012), H. 94 Y1 - 2012 SN - 0179-8529 SP - 12 EP - 14 PB - - ER - TY - JOUR A1 - Grotendorst, Johannes T1 - IAS Winter School: Hierarchical Methods for Dynamics in Complex Molecular Systems JF - Innovatives Supercomputing in Deutschland : inSiDE. 10 (2012), H. 1 Y1 - 2012 SP - 104 PB - - ER - TY - JOUR A1 - Grotendorst, Johannes T1 - Maple programs for converting series expansions to rational functions using the Levin transformation automatic generation of FORTRAN functions for numerical applications JF - Computer Physics Communications. 55 (1991), H. 3 Y1 - 1991 SN - 0010-4655 SP - 325 EP - 335 ER - TY - JOUR A1 - Grotendorst, Johannes T1 - Algorithms of mixed symbolic-numeric type for rational approximation JF - Artificial intelligence, expert systems and symbolic computing : selected and revised papers from the IMACS 13th World Congress [on Computation and Applied Mathematics], Dublin, Ireland, July 1991 / ed. by Elias N. Houstis ... Y1 - 1992 SN - 0-444-89703-8 N1 - zgl. Technical Report KFA-ZAM-IB-9205 ; World Congress on Computation and Applied Mathematics <13, 1991, Dublin> ; International Association for Mathematics and Computers in Simulation SP - 145 EP - 154 PB - North-Holland CY - Amsterdam ER - TY - JOUR A1 - Grotendorst, Johannes T1 - A Maple package for transforming series, sequences and functions JF - Computer Physics Communications. 67 (1991), H. 2 Y1 - 1991 SN - 0010-4655 SP - 325 EP - 342 ER - TY - JOUR A1 - Grotendorst, Johannes T1 - Approximating functions by means of symbolic computation and a general extrapolation method JF - Computer Physics Communications. 59 (1990), H. 2 Y1 - 1990 SN - 0010-4655 SP - 289 EP - 301 ER - TY - JOUR A1 - Grotendorst, Johannes A1 - Jansen, Paul A1 - Schoberth, Siegfried T1 - On Solving the McConnell Equations in Biochemistry / Grotendorst, Johannes ; Jansen, Paul ; Schoberth, Siegfried JF - MapleTech. 1 (1993) Y1 - 1993 SN - 1061-5733 N1 - zgl. Technical Report KFA-ZAM-IB-9314 ; The Maple Technical Newsletter SP - 56 EP - 62 ER - TY - JOUR A1 - Grotendorst, Johannes A1 - Schoberth, S. M. A1 - Chapman, B. E. A1 - Kuchel, P. W. T1 - Ethanol Transport in Zymomonas mobilis Measured by Using in Vivo Nuclear Magnetic Resonance Spin Transfer / Schoberth, S. M. ; Chapman, B. E. ; Kuchel, P. W. ; Wittig, R. M. ; Grotendorst, Johannes ; Jansen, Paul ; Graaf, A. A. de JF - Journal of Bacteriology. 178 (1996), H. 6 Y1 - 1996 SN - 0021-9193 SP - 1756 EP - 1761 ER - TY - JOUR A1 - Grotendorst, Johannes A1 - Shuang-Ren, Zhao A1 - Halling, Horst T1 - Calculation of the Potential Distribution for a Three-Layer Spherical Volume Conductor / Shuang-Ren, Zhao ; Grotendorst, Johannes ; Halling, Horst JF - MapleTech . 2 (1996), H. 1 Y1 - 1996 SN - 1061-5733 N1 - zugl. Technical Report KFA-ZAM-IB-9511 ; The Maple Technical Newsletters SP - 59 EP - 66 ER -