WAFO. The background

At the department of mathematical statistics, research related to level crossings in stochastic processes has been performed starting in the early 70's by Georg Lindgren [1]. Much work has been devoted to the problem of how to find statistical distributions for wave length and wave period for Gaussian processes, with obvious applications in oceanography and statistical analysis of fatigue of materials. Routines were originally written i Fortran, and in 1978 a computer program for wave-length and amplitude analysis of Gaussian waves, WAMP, was presented by Lindgren and Kenneth Holmström.

Further progress was made in the 80's, when a so-called regression approximation was developed by Igor Rychlik [2]. This made it possible to calculate distributions for characteristic wave parameters for a broader class of processes. A first collection of Matlab routines appeared in 1993, called Fatigue Analysis Toolbox (FAT). A co-worker at that time was Mats Frendahl. Some years later (1995), a Wave Analysis Toolbox (WAT) was developed. That toolbox focused on problems occuring in oceanography while still keeping routines from FAT for rainflow analysis of loads. Finn Lindgren made important contributions to WAT.

A fast development took place in 1999. Pär Johannesson, a PhD student in Lund, had written a Matlab toolbox for switching Markov chains. Further, Per A Brodtkorb (NTNU, Trondheim) was a visiting researcher in Lund. Many new routines were developed, with emphasis on applications from oceanography and marine technology, and old ones were made more efficient. The idea of updating WAT was born. Two further PhD students from Lund working with applications of random waves (Eva Sjö, and Jesper Rydén) were involved in the updating work, contributing with new routines and reorganising the stuff [3].

By the end of January 2000, a first version of WAFO was released on the Internet.An updated version for Unix was released by the end of May. Next version (2.0.1) was released at July 5, with an accompanying tutorial appearing July 6.

(For a complete list of references, see the Tutorial.)

  1. Lindgren, G. (1972). Wave-length and amplitude in Gaussian noise. Adv Appl Prob 4, pp. 81-108.
  2. Rychlik, I. (1987). Regression approximation of wave length and amplitude distributions. Adv Appl Prob 19, pp. 396-430.
  3. Brodtkorb, P.A., Johannesson, P., Lindgren, G., Rychlik, I., Rydén, J. and Sjö, E. (2000). WAFO - a Matlab toolbox for analysis of random waves and loads. Proceedings of the 10th International Offshore and Polar Engineering conference, Seattle, Vol III, pp. 343-350.

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Mathematical Statistics
Centre for Mathematical Sciences
Lund University with Lund Institute of Technology

Comments or corrections to Sofia Åberg
Last updated 2000-08-09