arXiv subjects
Publications and source records attributed to Joseph W. Rudmin.
A tutorial is presented which demonstrates the theory and usage of the Parker-Sochacki method of numerically solving systems of differential equations. Solutions are demonstrated for the case of projectile motion in air, and for the classical Newtonian N-body problem with mutual gravitational attraction.
An exact method of calculating the variance of a pooled data set is presented. Its major advantages over the many other methods are that it is simple, is easily derived and remembered, and requires no assumptions. The result can be concisely summarized as follows: "The Exact pooled variance is the mean of the variances plus the variance of the means of the component data sets." The proof is so simple that it has certainly been done many times before, but it is absent in the textbooks. Its practical significance is discussed.