Click here to Skip to main content
14,355,411 members

.NET Rational (fraction) value type using Decimals, written in C#

Rate this:
2.28 (6 votes)
Please Sign up or sign in to vote.
2.28 (6 votes)
24 Jan 2006CPOL
Implements a Rational datatype.


The class presented in this article implements a rational value type with basic mathematical functionality.

Using the code

This class has no public constructors.

Implicit casting to/from Int64 (and therefore other integer types) and decimal (and therefore float and double) is supported.

// Cast from int
PIEBALD.Types.Rational a = 1 ;
// Cast from double (via decimal)
PIEBALD.Types.Rational b = 2.3 ;
// Cast from decimal
PIEBALD.Types.Rational c = 4.5M ;

Conversion from decimal can be controlled by the ConversionMethod static property. Currently, the DecimalConversionMethod enumeration defines two values: Decimal and BestGuess. Decimal simply uses a power of ten as the denominator. BestGuess tries (with some success) to determine what numbers can be divided to produce the value.

// This is the default
PIEBALD.Types.Rational.ConversionMethod = 
// Yields 33333333333333333333
//    33333333/10000000000000000000000000000
PIEBALD.Types.Rational d = 1M / 3M ;
PIEBALD.Types.Rational.ConversionMethod = 
// Yields 1/3
PIEBALD.Types.Rational e = 1M / 3M ;

Strings containing expressions can be assigned with the ParseInfix and ParseRpn methods.

// Convert from string
PIEBALD.Types.Rational f = 
   PIEBALD.Types.Rational.ParseInfix ( "1/2" ) ;
// Convert from string
PIEBALD.Types.Rational g = 
   PIEBALD.Types.Rational.ParseInfix ( "(1/2) / (3/4)" ) ;
// Convert from string
PIEBALD.Types.Rational h = 
   PIEBALD.Types.Rational.ParseRpn ( "1 2 /" ) ;

See my PIEBALD.Lib.LibRpn class for information on how infix is transformed to RPN.

The mathematical operators (+, -, *, /, %, ^ (exponentiation)) are supported. There are other static and instance properties as well.


  • First posted - 2006/01/16.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Software Developer (Senior)
United States United States
BSCS 1992 Wentworth Institute of Technology

Originally from the Boston (MA) area. Lived in SoCal for a while. Now in the Phoenix (AZ) area.

OpenVMS enthusiast, ISO 8601 evangelist, photographer, opinionated SOB, acknowledged pedant and contrarian


"Using fewer technologies is better than using more." -- Rico Mariani

"Good code is its own best documentation. As you’re about to add a comment, ask yourself, ‘How can I improve the code so that this comment isn’t needed?’" -- Steve McConnell

"Every time you write a comment, you should grimace and feel the failure of your ability of expression." -- Unknown

"If you need help knowing what to think, let me know and I'll tell you." -- Jeffrey Snover [MSFT]

"Typing is no substitute for thinking." -- R.W. Hamming

"I find it appalling that you can become a programmer with less training than it takes to become a plumber." -- Bjarne Stroustrup

ZagNut’s Law: Arrogance is inversely proportional to ability.

"Well blow me sideways with a plastic marionette. I've just learned something new - and if I could award you a 100 for that post I would. Way to go you keyboard lovegod you." -- Pete O'Hanlon

"linq'ish" sounds like "inept" in German -- Andreas Gieriet

"Things would be different if I ran the zoo." -- Dr. Seuss

"Wrong is evil, and it must be defeated." –- Jeff Ello

"A good designer must rely on experience, on precise, logical thinking, and on pedantic exactness." -- Nigel Shaw

“It’s always easier to do it the hard way.” -- Blackhart

“If Unix wasn’t so bad that you can’t give it away, Bill Gates would never have succeeded in selling Windows.” -- Blackhart

"Use vertical and horizontal whitespace generously. Generally, all binary operators except '.' and '->' should be separated from their operands by blanks."

"Omit needless local variables." -- Strunk... had he taught programming

Comments and Discussions

GeneralLooks some code is missed. Pin
Member 257010323-Mar-09 2:51
memberMember 257010323-Mar-09 2:51 
GeneralRe: Looks some code is missed. Pin
PIEBALDconsult23-Mar-09 6:03
protectorPIEBALDconsult23-Mar-09 6:03 
GeneralRe: Looks some code is missed. Pin
Member 257010325-Mar-09 8:35
memberMember 257010325-Mar-09 8:35 
GeneralRe: Looks some code is missed. Pin
PIEBALDconsult25-Mar-09 9:39
protectorPIEBALDconsult25-Mar-09 9:39 
GeneralRe: Looks some code is missed. Pin
Member 257010325-Mar-09 21:05
memberMember 257010325-Mar-09 21:05 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

Posted 24 Jan 2006


13 bookmarked