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26 <div class=
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27 <a name=
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"link" href=
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"powm1">powm1
</a>
28 </h3></div></div></div>
29 <pre class=
"programlisting"><span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">boost
</span><span class=
"special">/
</span><span class=
"identifier">math
</span><span class=
"special">/
</span><span class=
"identifier">special_functions
</span><span class=
"special">/
</span><span class=
"identifier">powm1
</span><span class=
"special">.
</span><span class=
"identifier">hpp
</span><span class=
"special">></span>
31 <pre class=
"programlisting"><span class=
"keyword">namespace
</span> <span class=
"identifier">boost
</span><span class=
"special">{
</span> <span class=
"keyword">namespace
</span> <span class=
"identifier">math
</span><span class=
"special">{
</span>
33 <span class=
"keyword">template
</span> <span class=
"special"><</span><span class=
"keyword">class
</span> <span class=
"identifier">T1
</span><span class=
"special">,
</span> <span class=
"keyword">class
</span> <span class=
"identifier">T2
</span><span class=
"special">></span>
34 <a class=
"link" href=
"../result_type.html" title=
"Calculation of the Type of the Result"><span class=
"emphasis"><em>calculated-result-type
</em></span></a> <span class=
"identifier">powm1
</span><span class=
"special">(
</span><span class=
"identifier">T1
</span> <span class=
"identifier">x
</span><span class=
"special">,
</span> <span class=
"identifier">T2
</span> <span class=
"identifier">y
</span><span class=
"special">);
</span>
36 <span class=
"keyword">template
</span> <span class=
"special"><</span><span class=
"keyword">class
</span> <span class=
"identifier">T1
</span><span class=
"special">,
</span> <span class=
"keyword">class
</span> <span class=
"identifier">T2
</span><span class=
"special">,
</span> <span class=
"keyword">class
</span> <a class=
"link" href=
"../../policy.html" title=
"Chapter 15. Policies: Controlling Precision, Error Handling etc">Policy
</a><span class=
"special">></span>
37 <a class=
"link" href=
"../result_type.html" title=
"Calculation of the Type of the Result"><span class=
"emphasis"><em>calculated-result-type
</em></span></a> <span class=
"identifier">powm1
</span><span class=
"special">(
</span><span class=
"identifier">T1
</span> <span class=
"identifier">x
</span><span class=
"special">,
</span> <span class=
"identifier">T2
</span> <span class=
"identifier">y
</span><span class=
"special">,
</span> <span class=
"keyword">const
</span> <a class=
"link" href=
"../../policy.html" title=
"Chapter 15. Policies: Controlling Precision, Error Handling etc">Policy
</a><span class=
"special">&);
</span>
39 <span class=
"special">}}
</span> <span class=
"comment">// namespaces
</span>
42 Returns x
<sup>y
</sup> -
1.
45 The return type of this function is computed using the
<a class=
"link" href=
"../result_type.html" title=
"Calculation of the Type of the Result"><span class=
"emphasis"><em>result
46 type calculation rules
</em></span></a> when T1 and T2 are dufferent types.
49 The final
<a class=
"link" href=
"../../policy.html" title=
"Chapter 15. Policies: Controlling Precision, Error Handling etc">Policy
</a> argument is optional and can
50 be used to control the behaviour of the function: how it handles errors,
51 what level of precision to use etc. Refer to the
<a class=
"link" href=
"../../policy.html" title=
"Chapter 15. Policies: Controlling Precision, Error Handling etc">policy
52 documentation for more details
</a>.
55 There are two domains where this is useful: when y is very small, or when
59 Implemented in terms of
<code class=
"computeroutput"><span class=
"identifier">expm1
</span></code>.
62 The following graph illustrates the behaviour of powm1:
65 <span class=
"inlinemediaobject"><img src=
"../../../graphs/powm1.svg" align=
"middle"></span>
68 <a name=
"math_toolkit.powers.powm1.h0"></a>
69 <span class=
"phrase"><a name=
"math_toolkit.powers.powm1.accuracy"></a></span><a class=
"link" href=
"powm1.html#math_toolkit.powers.powm1.accuracy">Accuracy
</a>
72 Should have approximately
2-
3 epsilon accuracy.
75 <a name=
"math_toolkit.powers.powm1.table_powm1"></a><p class=
"title"><b>Table
 6.82.
 Error rates for powm1
</b></p>
76 <div class=
"table-contents"><table class=
"table" summary=
"Error rates for powm1">
89 Microsoft Visual C++ version
12.0<br> Win32
<br> double
94 GNU C++ version
5.1.0<br> linux
<br> double
99 GNU C++ version
5.1.0<br> linux
<br> long double
104 Sun compiler version
0x5130<br> Sun Solaris
<br> long double
116 <span class=
"blue">Max =
1.99ε (Mean =
0.461ε)
</span>
121 <span class=
"blue">Max =
1.26ε (Mean =
0.428ε)
</span>
126 <span class=
"blue">Max =
2.04ε (Mean =
0.521ε)
</span>
131 <span class=
"blue">Max =
2.14ε (Mean =
0.498ε)
</span>
137 <br class=
"table-break"><h5>
138 <a name=
"math_toolkit.powers.powm1.h1"></a>
139 <span class=
"phrase"><a name=
"math_toolkit.powers.powm1.testing"></a></span><a class=
"link" href=
"powm1.html#math_toolkit.powers.powm1.testing">Testing
</a>
142 A selection of random high precision test values calculated using NTL::RR
143 at
1000-bit precision.
146 <table xmlns:
rev=
"http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width=
"100%"><tr>
147 <td align=
"left"></td>
148 <td align=
"right"><div class=
"copyright-footer">Copyright
© 2006-
2010,
2012-
2014 Nikhar Agrawal,
149 Anton Bikineev, Paul A. Bristow, Marco Guazzone, Christopher Kormanyos, Hubert
150 Holin, Bruno Lalande, John Maddock, Jeremy Murphy, Johan R
åde, Gautam Sewani,
151 Benjamin Sobotta, Thijs van den Berg, Daryle Walker and Xiaogang Zhang
<p>
152 Distributed under the Boost Software License, Version
1.0. (See accompanying
153 file LICENSE_1_0.txt or copy at
<a href=
"http://www.boost.org/LICENSE_1_0.txt" target=
"_top">http://www.boost.org/LICENSE_1_0.txt
</a>)
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