Cnoidal wave is the wave height, "λ" is the wavelength, "c" is the phase speed and "η" is the trough elevation. Further cn is one of the Jacobi elliptic functions and "K"("m") is the complete elliptic integral of the first kind; both are dependent on the elliptic parameter "m". The latter, "m", determines the shape of the cnoidal wave. For "m" equal to zero the cnoidal wave becomes a cosine function, while for values close to one the cnoidal wave gets peaked crests and (very) flat troughs. For values of "m" less than 0.95, the cnoidal function can be approximated with trigonometric
Distance oracle auxiliary data structure. A simple data structure that achieves this goal is a "matrix" which specifies, for each pair of nodes, the distance between them. This structure allows us to answer queries in constant time formula_2, but requires formula_3 extra space. It can be initialized in time formula_4 using an all-pairs shortest paths algorithm, such as the Floyd–Warshall algorithm. A DO lies between these two extremes. It uses less than formula_3 space in order to answer queries in less than formula_1 time. Most DOs have to compromise on accuracy, i.e. they don't return the accurate distance but rather a constant-factor