Fields of activities of
Prof. Stiefel
3.3
| In all of
these areas Stiefel made truly original and fundamental contributions. In
fact, even as a newcomer to a field he was able to find a solution to some
important basic problem, and in retrospect, his solution was simple and
surprising at the same time. |
|
| With respect
to scientific computation, period 3 is the most important, but periods 4 and
5 must not be overlooked. The paramount contribution to numerical linear
algebra is of course the conjugate gradient algorithm introduced in the joint
paper with M. R. Hestenes and further investigated in a series of papers .
However, one should also mention Stiefels' promotion of the use of
variational principles for deriving the linear system from the physical
problem. With this approach he put difference methods on a common basis with
the finite-element method. |
|
| "Ambros
Speisers'( with Rutishauser his first collaborator at IAM) judgment in his
article “The Early Years of the Institute of Applied Mathematics” Stiefel had a remarkable intuitive insight of what was to become important in the future, an insight that he retained throughout his life. Without his foresight, the Institute( for Applied Mathematics) would not have been founded: None of his colleagues supported him, they followed, at a safe distance, the curious events that were occurring in room 16d. There is no doubt in my mind that Stiefel must be regarded as one of the outstanding figures at ETH in the 50s and 60s of this century." |