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149 lines
8.4 KiB
HTML
149 lines
8.4 KiB
HTML
4 years ago
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<html>
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<!-- This manual documents how to install and use the Multiple Precision
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Floating-Point Reliable Library, version 3.1.4.
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Copyright 1991, 1993-2016 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document under
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the terms of the GNU Free Documentation License, Version 1.2 or any later
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version published by the Free Software Foundation; with no Invariant Sections,
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with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the
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license is included in GNU Free Documentation License. -->
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<!-- Created by GNU Texinfo 6.4, http://www.gnu.org/software/texinfo/ -->
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<head>
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<title>MPFR Interface (GNU MPFR 3.1.4)</title>
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<meta name="description" content="How to install and use GNU MPFR, a library for reliable multiple precision
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floating-point arithmetic, version 3.1.4.">
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<meta name="keywords" content="MPFR Interface (GNU MPFR 3.1.4)">
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<meta name="resource-type" content="document">
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<meta name="distribution" content="global">
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<meta name="Generator" content="makeinfo">
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<link href="index.html#Top" rel="start" title="Top">
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<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index">
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<link href="index.html#Top" rel="up" title="Top">
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<link href="Initialization-Functions.html#Initialization-Functions" rel="next" title="Initialization Functions">
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<link href="Memory-Handling.html#Memory-Handling" rel="prev" title="Memory Handling">
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<style type="text/css">
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a.summary-letter {text-decoration: none}
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-->
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</style>
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</head>
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<body lang="en">
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<a name="MPFR-Interface"></a>
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<div class="header">
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<p>
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Next: <a href="API-Compatibility.html#API-Compatibility" accesskey="n" rel="next">API Compatibility</a>, Previous: <a href="MPFR-Basics.html#MPFR-Basics" accesskey="p" rel="prev">MPFR Basics</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> [<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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</div>
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<hr>
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<a name="MPFR-Interface-1"></a>
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<h2 class="chapter">5 MPFR Interface</h2>
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<a name="index-Floating_002dpoint-functions"></a>
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<a name="index-Float-functions"></a>
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<p>The floating-point functions expect arguments of type <code>mpfr_t</code>.
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</p>
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<p>The MPFR floating-point functions have an interface that is similar to the
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GNU MP
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functions. The function prefix for floating-point operations is <code>mpfr_</code>.
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</p>
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<p>The user has
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to specify the precision of each variable. A computation that assigns a
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variable will take place with the precision of the assigned variable; the
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cost of that computation should not depend on the
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precision of variables used as input (on average).
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</p>
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<a name="index-Precision-1"></a>
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<p>The semantics of a calculation in MPFR is specified as follows: Compute the
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requested operation exactly (with “infinite accuracy”), and round the result
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to the precision of the destination variable, with the given rounding mode.
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The MPFR floating-point functions are intended to be a smooth extension
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of the IEEE 754 arithmetic. The results obtained on a given computer are
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identical to those obtained on a computer with a different word size,
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or with a different compiler or operating system.
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</p>
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<a name="index-Accuracy"></a>
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<p>MPFR <em>does not keep track</em> of the accuracy of a computation. This is left
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to the user or to a higher layer (for example the MPFI library for interval
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arithmetic).
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As a consequence, if two variables are used to store
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only a few significant bits, and their product is stored in a variable with large
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precision, then MPFR will still compute the result with full precision.
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</p>
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<p>The value of the standard C macro <code>errno</code> may be set to non-zero by
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any MPFR function or macro, whether or not there is an error.
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</p>
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<table class="menu" border="0" cellspacing="0">
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<tr><td align="left" valign="top">• <a href="Initialization-Functions.html#Initialization-Functions" accesskey="1">Initialization Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Assignment-Functions.html#Assignment-Functions" accesskey="2">Assignment Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Combined-Initialization-and-Assignment-Functions.html#Combined-Initialization-and-Assignment-Functions" accesskey="3">Combined Initialization and Assignment Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Conversion-Functions.html#Conversion-Functions" accesskey="4">Conversion Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Basic-Arithmetic-Functions.html#Basic-Arithmetic-Functions" accesskey="5">Basic Arithmetic Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Comparison-Functions.html#Comparison-Functions" accesskey="6">Comparison Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Special-Functions.html#Special-Functions" accesskey="7">Special Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Input-and-Output-Functions.html#Input-and-Output-Functions" accesskey="8">Input and Output Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Formatted-Output-Functions.html#Formatted-Output-Functions" accesskey="9">Formatted Output Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Integer-Related-Functions.html#Integer-Related-Functions">Integer Related Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Rounding-Related-Functions.html#Rounding-Related-Functions">Rounding Related Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Miscellaneous-Functions.html#Miscellaneous-Functions">Miscellaneous Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Exception-Related-Functions.html#Exception-Related-Functions">Exception Related Functions</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Compatibility-with-MPF.html#Compatibility-with-MPF">Compatibility with MPF</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Custom-Interface.html#Custom-Interface">Custom Interface</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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<tr><td align="left" valign="top">• <a href="Internals.html#Internals">Internals</a>:</td><td> </td><td align="left" valign="top">
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</td></tr>
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</table>
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<hr>
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<div class="header">
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<p>
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Next: <a href="API-Compatibility.html#API-Compatibility" accesskey="n" rel="next">API Compatibility</a>, Previous: <a href="MPFR-Basics.html#MPFR-Basics" accesskey="p" rel="prev">MPFR Basics</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> [<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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</div>
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</body>
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</html>
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