**G.W. “Pete” Stewart**

Oral History (pdf)

**I****nterviewer:** Thomas Haigh

Numerical analyst G.W. (“Pete”) Stewart discusses the whole of his career to date. Born in 1940, Stewart spent his teenage years in Knoxville, Tennessee. In 1957 he enrolled in the University of Tennessee, where he majored in mathematics. Stewart graduated in 1963, winning a Woodrow Wilson fellowship for graduate study at Princeton. He stayed only one year, returning to his job at Oak Ridge where he remained until 1966 with exception of a year spent as a programmer in General Electric’s computer division. He enrolled in the Ph.D. program at the University of Tennessee, earning his Ph.D. in 1968 under the direction of Alston Householder. Stewart discusses his relationship with Householder, the computing facilities at the plant, a fellowship at the Oak Ridge National Laboratory, and his thesis work. After receiving his doctorate, Stewart spent four years as a member of the mathematics faculty at the University of Texas, Austin. During this period he created both the Bartels-Stewart method and his best known paper, a collaboration with Cleve Moler on what became known as the QZ algorithm for eigenvalue problems. After spending two years at Carnegie Mellon University, in 1974 he arrived at the University of Maryland, College Park where he has remained since. Stewart discusses the evolution of the computer science department over three decades. In the late 1970s Stewart, in collaboration with Cleve Moler, Jim Bunch, and Jack Dongarra, was one of the principle contributors to the LINPACK numerical linear algebra package and associated manual. He discusses the project’s origins, scope, methods, and impact together with the work of each project member. Stewart also surveys the most significant of his many research papers and contributions to mathematical methods, his text books in the field and his interest in the translation of historical mathematical works. He explores his involvement in several professional bodies, including the ACM’s SIGNUM, SIAM, and the Gatlinbugh/Householder meetings.

**Key words:** QZ algorithm, QR algorithm, LINPACK, EISPACK

**Funding Agency:** Department of Energy, National Science Foundation, Office of Naval Research

**Time frame:** 1960's, 1970's, 1980's

**People:** Alston Householder, R.H. Bartels, Cleve Moler, Jim Bunch, Jack Dongarra, Gene Golub, William Kahan, Jim Wilkinson, Dianne O’Leary

**Location:** University of Tennessee, Oak Ridge National Laboratory, University of Texas- Austin, Carnegie Mellon University, University of Maryland, College Park

**Citation:** G.W. “Pete” Stewart: Oral history interview by Thomas Haigh, 5 - 6 March, 2006, Washington D.C. Society for Industrial and Applied Mathematics, Philadelphia, PA

**Statement of Use Policy**: Copyright © by the Society for Industrial and Applied Mathematics (SIAM). Use of this the material for research purposes is allowed. Any such use should cite the SIAM History of Numerical Analysis and Scientific Computing Project (http://history.siam.org). Use of the oral history materials for commercial purposes requires the written permission of the Computer History Museum. Contact the Computer History Museum, 1401 N Shoreline Boulevard, Mountain View, CA 94043-1311 USA for permissions.