James Demmel

Professor of Mathematics and Computer Science
Dr. Richard Carl Dehmel Distinguished Professor
Former Chief Scientist of CITRIS, the Center for Information Technology Research in the Interest of Society

Office:

831 EVANS HALL (new office, as of 27 May 2008)
Department of Mathematics
Computer Science Division
University of California at Berkeley
Spring 2008 - on sabbatical (office hours by appointment)
Berkeley CA 94720-1776
Email: demmel@cs.berkeley.edu
Office: (510) 643-5386
FAX: (510) 642-3962

Administrative Assistant:
Tammy Johnson
Office: 719 Soda
Email: tamille@eecs.berkeley.edu
Telephone: (510)643-4816

Grants Administrator:
Sherry Liang
Office: 776 Soda
Email: liangs@eecs.berkeley.edu
Telephone: (510)643-1980

Teaching:

Guest Lectures for Spring 2008: CS 267, Applications of Parallel Computers
Teaching for Fall 2007: Math 55, Discrete Mathematics
Guest Lectures for Spring 2007: CS 267, Applications of Parallel Computers
Teaching for Spring 2007: CS 170, Efficient Algorithms and Intractable Problems
Teaching for Spring 2006: CS 267, Applications of Parallel Computers
Teaching for Fall 2005: Math 110, Linear Algebra
Teaching for Spring 2005: CS 267, Applications of Parallel Computers
Teaching for Fall 2004: Math 221, Matrix Computations
Teaching for Spring 2004: Math 55, Discrete Mathematics
Teaching for Spring 2002: Math 128a, Numerical Analysis
Teaching for Spring 2001: CS 170, Efficient Algorithms and Intractable Problems (co-taught by Prof. Jonathan Shewchuk)
Teaching for Fall 2000: Math 55, Discrete Mathematics
Teaching for Fall 1999: CS 170, Efficient Algorithms and Intractable Problems
Teaching for Fall 1999: Math 221, Matrix Computations
Teaching for Spring 1999: CS 267, Applications of Parallel Computers
Teaching for Fall 1998: Math 128a, Numerical Analysis
Teaching for Spring 1998: CS 170, Efficient Algorithms and Intractable Problems
Teaching for Fall 1997: Math 221, Matrix Computations

Selected Awards:

Distinguished Alumnus Award in Computer Sciences and Engineering, UC Berkeley, 2004
IEEE Fellow, 2001
National Academy of Engineering, 1999
ACM Fellow, 1999
NSF-CBMS Lecturer on Parallel Numerical Linear Algebra, San Francisco, 1995
J. H. Wilkinson Prize in Numerical Analysis and Scientific Computing, 1993
SIAG on Linear Algebra Prize 1991 (with W. Kahan) and 1988
Presidential Young Investigator Award, 1986
IBM Faculty Development Award, 1985

Research Projects and Books:

Avoiding Communication in Dense and Sparse Linear Algebra, a presentation in ppt

Proposal to update the LAPACK and ScaLAPACK linear algebra libraries, in pdf or postscript.

  • Presentation in ppt on Sca/LAPACK research and development plans
  • Extra-Precise Iterative Refinement (pdf), a technical report describing the proposed LAPACK implementation of iterative refinement of solutions of linear systems
  • Complete data for numerical experiments summarized in the technical report.
  • CITRIS is the Center for Information Technology Research in the interest of Society, a new $300M multicampus research center with the mandate of creating information technology to tackle society's most critical needs. Initial CITRIS research will focus on energy efficiency, transportation, disaster response, health care, education and environmental monitoring.

  • Long CITRIS Overview Presentation, (updated September 2003) (in PowerPoint)
  • Short CITRIS Overview Presentation, (updated March 2003) (in PowerPoint)
  • Long CITRIS Overview Presentation, (updated February 2003) (in PowerPoint)
  • CITRIS Networking Workshop, 1 March 2002 (in PowerPoint)
  • CITRIS Seminar, 7 Feb 2002 (in PowerPoint)
  • Next Generation Internet Incubator (CommerceNet)
  • SUGAR is a simulation tool for MEMS (MicroElectroMechanical Systems), tiny sensors and actuators that form a pillar of CITRIS's approach to solving large scale societal problems. SUGAR is used by many researchers in the Berkeley Sensor and Actuator Center (BSAC).

  • BSAC IAB Presentation, 12 March 2002 (in PowerPoint)
  • SUGAR Overview, Feb 2001 (in PowerPoint)
  • BeBOP is Berkeley Benchmarking and OPtimization Group. We work on automatic performance optimization of numerical kernels, tuning them to run as fast as possible for particular architectures and sometimes particular inputs.

  • CS 258 Guest Lecture on Performance Tuning, 13 March, 2002 (in PowerPoint)
  • High Performance Information Retrieval and MEMS CAD, 11 Dec, 2001 (in PowerPoint)
  • Selected Papers and Reports
  • Millennium is a campus-wide project to provide hardward and sofware facilities for high performance computing. My activities are to provide algorithms, software and advice to best facilitate computational science and engineering on campus.

  • SimMillennium: Computer Systems, Computational Science and Engineering in the Large, Aug 1999 (in PowerPoint)
  • The Complexity of Accurate Floating Point Computation. See below for recent talks.

  • Towards accurate polynomial evaluation, or When can Numerical Linear Algebra be done accurately?
    Slides in pdf. presented at FOCM 2005. (updated version of following talk)
  • The Cost of Accurate Numerical Linear Algebra, or Can we evaluate polynomials accurately?
    Slides in pdf. presented at IWASEP 5.
  • Necessary Conditions for Accurate Evaluation of Polynomials. Slides presented at MSRI Workshop on Applications of Real Algebraic Geometry, April 2004, in postscript or pdf.
  • The Complexity of Accurate Floating Point Computation. Slides presented at ICM 2002, in postscript or pdf. (See below for longer versions of this talk.)
  • The Complexity of Accurate Floating Point Computation. In postscript or pdf. In Proc. ICM 2002, Beijing.
  • Accurate and Efficient Computations with Structured Matrices UC Berkeley PhD Dissertation by Plamen Koev.
  • Templates for the Solution of Algebraic Eigenvalue Problems: This book gives a unified overview of the theory, algorithms and practical software for eigenvalue problems. It organizes this large body of material to make it accessible for the first time to experts and non-experts who need to choose the best state-of-the-art algorithms and software for their problems.

    LAPACK - Linear Algebra PACKage for high performance workstations and shared memory parallel computers. The LAPACK Manual is available on-line.

    (This and much other useful numerical software is available on Netlib.)

    ScaLAPACK - Scalable Linear Algebra PACKage for high performance distributed memory parallel computers, The ScaLAPACK Manual is available on-line.

    Proposal to update the LAPACK and ScaLAPACK linear algebra libraries.

    SuperLU, implementations of sparse Gaussian Elimination for high performance parallel machines

    Templates for the Solution of Linear Systems: Building Blocks for Iterative Methods is a hyper-text book on iterative methods for solving systems of linear equations. A similar book project for eigenvalue problems is underway.

    Selected Recent Talks:

    Avoiding Communication in Dense and Sparse Linear Algebra, a presentation in ppt, presented at the Householder Symposium 2008
  • Version (in powerpoint2003) presented at MMDS 2008
  • Der Zahlenlehrling / The Numerical Apprentice, a poem (in ppt) in memory of Gene Golub, presented at the Householder Symposium 2008
    A Celebration of William Kahan and Beresford Parlett, a speech given at Bay Area Scientific Computing Day 2008, in PowerPower2003 (8.6MB) or pdf (3.6MB).
    The Future of LAPACK and ScaLAPACK (in powerpoint), presented at PARA 06 meeting, Umea, Sweden, June 2006
    Towards Accurate Polynomial Evaluation, or When can Numerical Linear Algebra be done accurately? (in pdf), presented at Banff meeting, October, 2005
    The future of numerical linear algebra: Automatic Performance Tuning of Sparse Matrix Kernels, and The Next LAPACK and ScaLAPACK. In powerpoint.
    The Cost of Accurate Numerical Linear Algebra, or Can we evaluate polynomials accurately?
    In pdf. Slides presented at IWASEP 5.
    The Complexity of Accurate Floating Point Computation, or Can we do Numerical Linear Algebra in Polynomial Time?
    In postscript or pdf. Slides presented at the Householder Symposium XV, 2002 and IWASEP 4. Earlier version presented at ISSAC 2001.
    Scaling in Numerical Linear Algebra, Scaling to New Heights, Pittsburgh Supercomputer Center, 20 May 2002 (in PowerPoint)
    CITRIS Seminar, 7 Feb 2002 (in PowerPoint)
    Guest Lecture on Dense Linear Algebra for CS267 (Fall 2001, in PowerPoint)
    High performance Information Retrieval and MEMS CAD on Intel Itanium (in PowerPoint) UCB EECS Department Talk, Oct 12, 2001. (Version from 11 Dec, 2001)
    CITRIS - Center for Information Technology Research in the Interest of Society (in PowerPoint) UCB EECS Department Colloquium, Oct 10, 2001.
    The Complexity of Accurate Floating Point Computation in postscript or in pdf.
    Recent Progress in High Accuracy and High Performance Linear Algebra Algorithms May 4, 1999. Solving systems of linear equations, and finding eigenvalues of symmetric matrices are standard problems that arise in many mathematical modeling problems. Solutions have existed for a long time, but these solutions are no longer good enough, because the demands of applications keep growing to larger problems, and to more ``sensitive'' problems that require higher accuracy. In addition, the larger problems in turn require large parallel computerswhere communication is much more expensive than computation.
    We highlight several new algorithms under development, all of which have solved linear systems and eigenvalue problems many times larger, more sensitive or more quickly than before. Though these algorithms are all very different, one common mathematical approach distinguishes them from their predecessors: The new algorithms deliberately throw away just enough information about the problem to run both efficiently yet accurately. In contrast, their predecessors would either have to use much higher precision, send many more messages, or do many more operations to get the same answers.
    Recent Progress in High Accuracy and High Performance Linear Algebra Algorithms May 13, 1999. This version of the above talk was an invited presentation at the 1999 SIAM Annual Meeting.
    Survey of Parallel Numerical Linear Algebra Libraries Aug 20, 1997. This survey of dense and sparse parallel numerical linear algebra libraries covered a variety of available software for dense and sparse linear algebra problems on parallel computers, including LAPACK, ScaLAPACK, SuperLU and others. It was presented at a short course for NPACI (at the San Diego Supercomputer Center).

    Current Graduate Students:

    Yozo Hida
    Mark Hoemmen
    Jason Riedy
    Vasily Volkov
    William Kramer

    Undergraduate Research Students:

    Meghana Vishvanath
    Deaghlan Halligan
    Ankit Jain
    Weihua Shen
    Berkat Tung
    Michael DeLorimer
    Shoaib Kamil
    Jimmy Iskandar
    Anil Kapur
    Michael Martin
    Brandon Thompson
    Teresa Tung
    Daniel Yoo
    Ben Wanzo
    Suh Kang
    Henry Chen
    Josh Genauer

    Gone but not forgotten:

    Jiawang Nie
    Plamen Koev
    David Garmire
    David Bindel
    Tzu-Yi Chen
    Howard Robinson
    Mark Adams
    David Blackston
    Chee-whye Chin
    Inderjit Dhillon
    Balazs Kralik
    Dominic Lam
    Xiaoye Li
    Huan Ren
    Sharon Smith
    Ken Stanley
    Jinqchong Teo
    Oleg Zakharov
    Melody Ivory
    Andrei Zege

    More on Teaching Activities:

    Math 128a is a one semester upper division course on numerical analysis.

    CS 170 is a one semester upper division course on efficient algorithms and intractable problems.

    Math 221 is a one semester course in matrix computations. My text for the course, Applied Numerical Linear Algebra, was published by SIAM in August 1997.

    CS 267 is a one-semester graduate class in Applications of Parallel Computers.

    (Fall 2001 version of CS 267), offered by Prof. Katherine Yelick)

    NSF-CBMS Short Course on Parallel Numerical Linear Algebra, held summer 1995, and based on the Spring 1995 version of CS 267.

    Computational Science Education Project provides an on-line text book on high-performance computing. I co-authored the chapter on Parallel Numerical Linear Algebra

    Math 55 is a one-semester undergraduate course in discrete mathematics, offered Spring semester 1997.

    Biographical Sketch:

    James Demmel received his BS in Mathematics from Caltech in 1975 and his Ph.D. in Computer Science from UC Berkeley in 1983. After spending six years on the faculty of the Courant Institute , New York University , he joined the Computer Science Division and Mathematics Department at Berkeley in 1990, where he holds a joint appointment.