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Mathematical Programs

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**Most are made available under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, but see the License conditions for each individual program.**

### Date of Easter

There are many programs which compute the date of Easter Sunday.

This is a demonstration of the method described in the Book of Common Prayer.

Date of Easter.

### Divison by Multiplication

The Ferranti Mercury Computer (circa 1957) had a floating-point arithmetic unit but did not
have a floating-point divide instruction. Floating-point division was performed by scaling the
number into the range [0.5, 1.0) and then computing the reciprocal using a Newton-Raphson
iteration. The result was then rescaled appropriately.

This is a demonstration of the method used on the Mercury.

Divison by Multiplication.

### Drawing Ellipses Using a Shear Transformation

This is a demonstration of using a shear transformation to draw ellipses.
It is based on a paper by Nathan Dinsmore.

Drawing Ellipses.

### Roman Arithmetic

This is a demonstration of the methods that may have been used to perform calculations with
numbers represented in Roman Numerals.

Roman Arithmetic.

Last updated Friday, March 18, 2016.