<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!--Rendered using the Haskell Html Library v0.2--> <HTML ><HEAD ><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8" ><TITLE >Data.Ratio</TITLE ><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css" ><SCRIPT SRC="haddock-util.js" TYPE="text/javascript" ></SCRIPT ><SCRIPT TYPE="text/javascript" >window.onload = function () {setSynopsis("mini_Data-Ratio.html")};</SCRIPT ></HEAD ><BODY ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="topbar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" " ></TD ><TD CLASS="title" >base-4.1.0.0: Basic libraries</TD ><TD CLASS="topbut" ><A HREF="index.html" >Contents</A ></TD ><TD CLASS="topbut" ><A HREF="doc-index.html" >Index</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="modulebar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><FONT SIZE="6" >Data.Ratio</FONT ></TD ><TD ALIGN="right" ><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="infohead" >Portability</TD ><TD CLASS="infoval" >portable</TD ></TR ><TR ><TD CLASS="infohead" >Stability</TD ><TD CLASS="infoval" >stable</TD ></TR ><TR ><TD CLASS="infohead" >Maintainer</TD ><TD CLASS="infoval" >libraries@haskell.org</TD ></TR ></TABLE ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Description</TD ></TR ><TR ><TD CLASS="doc" >Standard functions on rational numbers </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Synopsis</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >data</SPAN > <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="#t%3ARatio" >Ratio</A > a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >type</SPAN > <A HREF="#t%3ARational" >Rational</A > = <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > <A HREF="../integer/GHC-Integer.html#t%3AInteger" >Integer</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3A%25" >(%)</A > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => a -> a -> <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3Anumerator" >numerator</A > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a -> a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3Adenominator" >denominator</A > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a -> a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AapproxRational" >approxRational</A > :: <A HREF="Prelude.html#t%3ARealFrac" >RealFrac</A > a => a -> a -> <A HREF="Data-Ratio.html#t%3ARational" >Rational</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Documentation</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >data</SPAN > <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A NAME="t:Ratio" ><A NAME="t%3ARatio" ></A ></A ><B >Ratio</B > a </TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="ndoc" >Rational numbers, with numerator and denominator of some <TT ><A HREF="Prelude.html#t%3AIntegral" >Integral</A ></TT > type. </TD ></TR ><TR ><TD CLASS="section4" ><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:Ratio')" ALT="show/hide" > Instances</TD ></TR ><TR ><TD CLASS="body" ><DIV ID="i:Ratio" STYLE="display:block;" ><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="Data-Typeable.html#t%3ATypeable1" >Typeable1</A > <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Prelude.html#t%3AEnum" >Enum</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Eq.html#t%3AEq" >Eq</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Prelude.html#t%3AFractional" >Fractional</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" >(<A HREF="Data-Data.html#t%3AData" >Data</A > a, <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a) => <A HREF="Data-Data.html#t%3AData" >Data</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Prelude.html#t%3ANum" >Num</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Ord.html#t%3AOrd" >Ord</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" >(<A HREF="Prelude.html#t%3AIntegral" >Integral</A > a, <A HREF="Text-Read.html#t%3ARead" >Read</A > a) => <A HREF="Text-Read.html#t%3ARead" >Read</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Prelude.html#t%3AReal" >Real</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Prelude.html#t%3ARealFrac" >RealFrac</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ><TR ><TD CLASS="decl" ><A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Text-Show.html#t%3AShow" >Show</A > (<A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a)</TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><SPAN CLASS="keyword" >type</SPAN > <A NAME="t:Rational" ><A NAME="t%3ARational" ></A ></A ><B >Rational</B > = <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > <A HREF="../integer/GHC-Integer.html#t%3AInteger" >Integer</A ></TD ></TR ><TR ><TD CLASS="doc" >Arbitrary-precision rational numbers, represented as a ratio of two <TT ><A HREF="../integer/GHC-Integer.html#t%3AInteger" >Integer</A ></TT > values. A rational number may be constructed using the <TT ><A HREF="Data-Ratio.html#v%3A%25" >%</A ></TT > operator. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:%" ><A NAME="v%3A%25" ></A ></A ><B >(%)</B > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => a -> a -> <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a</TD ></TR ><TR ><TD CLASS="doc" >Forms the ratio of two integral numbers. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:numerator" ><A NAME="v%3Anumerator" ></A ></A ><B >numerator</B > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a -> a</TD ></TR ><TR ><TD CLASS="doc" >Extract the numerator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:denominator" ><A NAME="v%3Adenominator" ></A ></A ><B >denominator</B > :: <A HREF="Prelude.html#t%3AIntegral" >Integral</A > a => <A HREF="Data-Ratio.html#t%3ARatio" >Ratio</A > a -> a</TD ></TR ><TR ><TD CLASS="doc" >Extract the denominator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:approxRational" ><A NAME="v%3AapproxRational" ></A ></A ><B >approxRational</B > :: <A HREF="Prelude.html#t%3ARealFrac" >RealFrac</A > a => a -> a -> <A HREF="Data-Ratio.html#t%3ARational" >Rational</A ></TD ></TR ><TR ><TD CLASS="doc" ><P ><TT ><A HREF="Data-Ratio.html#v%3AapproxRational" >approxRational</A ></TT >, applied to two real fractional numbers <TT >x</TT > and <TT >epsilon</TT >, returns the simplest rational number within <TT >epsilon</TT > of <TT >x</TT >. A rational number <TT >y</TT > is said to be <EM >simpler</EM > than another <TT >y'</TT > if </P ><UL ><LI > <TT ><TT ><A HREF="Prelude.html#v%3Aabs" >abs</A ></TT > (<TT ><A HREF="Data-Ratio.html#v%3Anumerator" >numerator</A ></TT > y) <= <TT ><A HREF="Prelude.html#v%3Aabs" >abs</A ></TT > (<TT ><A HREF="Data-Ratio.html#v%3Anumerator" >numerator</A ></TT > y')</TT >, and </LI ><LI > <TT ><TT ><A HREF="Data-Ratio.html#v%3Adenominator" >denominator</A ></TT > y <= <TT ><A HREF="Data-Ratio.html#v%3Adenominator" >denominator</A ></TT > y'</TT >. </LI ></UL ><P >Any real interval contains a unique simplest rational; in particular, note that <TT >0/1</TT > is the simplest rational of all. </P ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="botbar" >Produced by <A HREF="http://www.haskell.org/haddock/" >Haddock</A > version 2.4.2</TD ></TR ></TABLE ></BODY ></HTML >