Wolfram Library Archive

All Collections Articles Books Conference Proceedings
Courseware Demos MathSource Technical Notes
Title Downloads

PtolemyChordTable.m 1.1

Nathan Sidoli
Organization: na
Old MathSource #

Revision date


This package defines a number of functions which facilitate working with Ptolemy's trigonometry. It was written for the student of Ptolemy's mathematical astronomy, particularly his Almagest. The main benefit of PtolemyChordTable.m is that it saves one the tedium of repeatedly referring to the chord table in the Almagest while working through his calculations.

The first version (1.0) was written in 1998. I have updated the package while writing my dissertation. The final revision to the current version (1.1) was made in 2003. It contains a number of new functions. In particular one can now convert a sexagesimal number of at most six places in the form n1;n2,...,nk to a rational number with the function PtolemyRational[n1,...,nk]. See the package file for other additions. In the future I plan to implement some of Ptolemy's other tables.

In following the calculations in the Almagest, I never found any use for the more involved trigonometric functions (PtolemyCosRule[x] and PtolemySinRule[x]). They will probably be cut from future versions.

The notebook file PtolemyChordTableExample.nb has not been updated and I would probably write it differently now. Nevertheless, it contains some examples that users may find useful.

*Science > Astronomy

Ptolemy, trigonometry, history of mathematics, history of astronomy, chord table, triangulation, epicycle, eccentric
Downloads Download Wolfram CDF Player

PtolemyChordTable.m (32.8 KB) - Mathematica Package [for Mathematica 5.0]
PtolemyChordTableExample.nb (43.8 KB) - Example notebook for PtolemyChordTable.m [for Mathematica 5.0]