WAFO (Wave Analysis for Fatigue and Oceanography) is a toolbox of Matlab routines for statistical analysis and simulation of random waves and random loads. An important part are routines for calculation of theoretical distributions of wave characteristics from observed or theoretical power spectra of the sea. A new philosophy concerning documentation is presented. The toolbox contains scripts for generation of plots in recent publications and scripts for comparison with results in the literature. The theoretical density of rainflow cycles can be computed from parameters of random loads.
In a random wave model, like that for Gaussian or transformed Gaussian waves, the distribution of wave characteristics such as wave period and crest-trough wave height can be calculated by high accuracy for almost any spectral type. WAFO is a thirdgeneration package of Matlab routines for handling statistical modelling, calculation and analysis of random waves and wave characteristics and their statistical distributions. The package also contains routines for cycle counting and computation in random load models, in particular the ralnflow counting often used in fatigue life prediction. Random wave distributions are notoriously difficult to obtain in explicit form from a random wave model, but numerical algorithms, based on the so-called regression approximation, work well. This method to calculate wave distributions is the only known method that gives correct answers valid for general spectra. The theoretical background is reviewed in Lindgren and Rychlik (1991) and computational aspects and algorithms in Rychlik and Lindgren (1993). The algorithms are based on a specification of the random waves by means of their (uni-directional or directional) spectrum, and on the underlying assumption of linear wave theory and Gaussian distribution. However, a transformation of sea elevation data can be made to obtain a desired (horizontal) asymmetric marginal distribution.
