Fantasy tabletop role-playing game (RPG). Some

The Rybicki–Press algorithm is a fast algorithm for inverting a matrix whose entries are given by , where and where the are sorted in order. The key observation behind the Rybicki-Press observation is that the matrix inverse of such a matrix is always a tridiagonal matrix, and tridiagonal systems of equations can be solved efficiently. It is a computational optimization of a general set of statistical methods developed to determine whether two noisy, irregularly sampled data sets are, in fact, dimensionally shifted representations of the same underlying function. The most common use of the algorithm is in the detection of periodicity in astronomical observations, such as for detecting quasars.

Stephen R. \"Steve\" Marsh is an American game designer and lawyer best known for his contributions to early editions of TSR's Dungeons & Dragons fantasy tabletop role-playing game (RPG). Some of the creatures he created for the original edition of D&D in 1975 have been included in every subsequent edition of the game.