Johan Frederik Steffensen
Encyclopedia
Johan Frederik Steffensen (1873–1961) was a Danish mathematician, statistician
, and actuary
who did research in the fields of calculus of finite differences and interpolation
. He was professor of actuarial science at the University of Copenhagen from 1923 to 1943. Steffensen's inequality and Steffensen's method
(an iterative numerical method) are named after him.
Statistician
A statistician is someone who works with theoretical or applied statistics. The profession exists in both the private and public sectors. The core of that work is to measure, interpret, and describe the world and human activity patterns within it...
, and actuary
Actuary
An actuary is a business professional who deals with the financial impact of risk and uncertainty. Actuaries provide expert assessments of financial security systems, with a focus on their complexity, their mathematics, and their mechanisms ....
who did research in the fields of calculus of finite differences and interpolation
Interpolation
In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points....
. He was professor of actuarial science at the University of Copenhagen from 1923 to 1943. Steffensen's inequality and Steffensen's method
Steffensen's method
In numerical analysis, Steffensen's method is a root-finding method, similar to Newton's method, named after Johan Frederik Steffensen. Steffensen's method also achieves quadratic convergence, but without using derivatives as Newton's method does....
(an iterative numerical method) are named after him.
Obituary
N. E. Nordlund, Johan Frederik Steffensen in memoriam, Nordisk Matematisk Tidsskrift, 10 (1962) 105-107.External links
- Johan Frederik Steffensen papirer (Danish)