kepler5

**Celestial Mechanics on a Graphing Calculator**

## 5. The TI-82 programs

This column used 4 programs written in the TI version of BASIC. They should be easily convertible to any other form of that language. In these programs the list `L`_{1} acts like the 4-component vector `(x,y,v,w)`. The windows are adjustable inside the programs, and are set for initial conditions similar to those used in the column. The input `L`_{1} must be given as a list inside curly brackets {}. The other inputs requested are `B` the stopping time, `N` the number of steps, or `M` the maximum velocity rotation tolerance, as appropriate. In RK-ADAPT the *sine* of the angle between the old velocity vector and the new is compared with the tolerance. The three programs EULER4, RK and RK-ADAPT all use the program KSUB as subroutine.

Welcome to the
Feature Column!

These web essays are designed for those who have already discovered the joys of mathematics as well as for those who may be uncomfortable with mathematics.

Read more . . .

Feature Column at a glance