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| <a name="glib-Numerical-Definitions"></a><div class="titlepage"></div> |
| <div class="refnamediv"><table width="100%"><tr> |
| <td valign="top"> |
| <h2><span class="refentrytitle"><a name="glib-Numerical-Definitions.top_of_page"></a>Numerical Definitions</span></h2> |
| <p>Numerical Definitions — mathematical constants, and floating point decomposition</p> |
| </td> |
| <td class="gallery_image" valign="top" align="right"></td> |
| </tr></table></div> |
| <div class="refsect1"> |
| <a name="glib-Numerical-Definitions.other"></a><h2>Types and Values</h2> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="150px" class="name"> |
| <col class="description"> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-IEEE754-FLOAT-BIAS:CAPS" title="G_IEEE754_FLOAT_BIAS">G_IEEE754_FLOAT_BIAS</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-IEEE754-DOUBLE-BIAS:CAPS" title="G_IEEE754_DOUBLE_BIAS">G_IEEE754_DOUBLE_BIAS</a></td> |
| </tr> |
| <tr> |
| <td class="datatype_keyword">union</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#GFloatIEEE754" title="union GFloatIEEE754">GFloatIEEE754</a></td> |
| </tr> |
| <tr> |
| <td class="datatype_keyword">union</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#GDoubleIEEE754" title="union GDoubleIEEE754">GDoubleIEEE754</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-E:CAPS" title="G_E">G_E</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-LN2:CAPS" title="G_LN2">G_LN2</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-LN10:CAPS" title="G_LN10">G_LN10</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-PI:CAPS" title="G_PI">G_PI</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-PI-2:CAPS" title="G_PI_2">G_PI_2</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-PI-4:CAPS" title="G_PI_4">G_PI_4</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-SQRT2:CAPS" title="G_SQRT2">G_SQRT2</a></td> |
| </tr> |
| <tr> |
| <td class="define_keyword">#define</td> |
| <td class="function_name"><a class="link" href="glib-Numerical-Definitions.html#G-LOG-2-BASE-10:CAPS" title="G_LOG_2_BASE_10">G_LOG_2_BASE_10</a></td> |
| </tr> |
| </tbody> |
| </table></div> |
| </div> |
| <div class="refsect1"> |
| <a name="glib-Numerical-Definitions.includes"></a><h2>Includes</h2> |
| <pre class="synopsis">#include <glib.h> |
| </pre> |
| </div> |
| <div class="refsect1"> |
| <a name="glib-Numerical-Definitions.description"></a><h2>Description</h2> |
| <p>GLib offers mathematical constants such as <a class="link" href="glib-Numerical-Definitions.html#G-PI:CAPS" title="G_PI"><span class="type">G_PI</span></a> for the value of pi; |
| many platforms have these in the C library, but some don't, the GLib |
| versions always exist.</p> |
| <p>The <a class="link" href="glib-Numerical-Definitions.html#GFloatIEEE754" title="union GFloatIEEE754"><span class="type">GFloatIEEE754</span></a> and <a class="link" href="glib-Numerical-Definitions.html#GDoubleIEEE754" title="union GDoubleIEEE754"><span class="type">GDoubleIEEE754</span></a> unions are used to access the |
| sign, mantissa and exponent of IEEE floats and doubles. These unions are |
| defined as appropriate for a given platform. IEEE floats and doubles are |
| supported (used for storage) by at least Intel, PPC and Sparc. See |
| <a class="ulink" href="http://en.wikipedia.org/wiki/IEEE_float" target="_top">IEEE 754-2008</a> |
| for more information about IEEE number formats.</p> |
| </div> |
| <div class="refsect1"> |
| <a name="glib-Numerical-Definitions.functions_details"></a><h2>Functions</h2> |
| <p></p> |
| </div> |
| <div class="refsect1"> |
| <a name="glib-Numerical-Definitions.other_details"></a><h2>Types and Values</h2> |
| <div class="refsect2"> |
| <a name="G-IEEE754-FLOAT-BIAS:CAPS"></a><h3>G_IEEE754_FLOAT_BIAS</h3> |
| <pre class="programlisting">#define G_IEEE754_FLOAT_BIAS (127) |
| </pre> |
| <p>The bias by which exponents in single-precision floats are offset.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-IEEE754-DOUBLE-BIAS:CAPS"></a><h3>G_IEEE754_DOUBLE_BIAS</h3> |
| <pre class="programlisting">#define G_IEEE754_DOUBLE_BIAS (1023) |
| </pre> |
| <p>The bias by which exponents in double-precision floats are offset.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GFloatIEEE754"></a><h3>union GFloatIEEE754</h3> |
| <p>The <a class="link" href="glib-Numerical-Definitions.html#GFloatIEEE754" title="union GFloatIEEE754"><span class="type">GFloatIEEE754</span></a> and <a class="link" href="glib-Numerical-Definitions.html#GDoubleIEEE754" title="union GDoubleIEEE754"><span class="type">GDoubleIEEE754</span></a> unions are used to access the sign, |
| mantissa and exponent of IEEE floats and doubles. These unions are defined |
| as appropriate for a given platform. IEEE floats and doubles are supported |
| (used for storage) by at least Intel, PPC and Sparc.</p> |
| <div class="refsect3"> |
| <a name="GFloatIEEE754.members"></a><h4>Members</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="300px" class="union_members_name"> |
| <col class="union_members_description"> |
| <col width="200px" class="union_members_annotations"> |
| </colgroup> |
| <tbody></tbody> |
| </table></div> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="GDoubleIEEE754"></a><h3>union GDoubleIEEE754</h3> |
| <p>The <a class="link" href="glib-Numerical-Definitions.html#GFloatIEEE754" title="union GFloatIEEE754"><span class="type">GFloatIEEE754</span></a> and <a class="link" href="glib-Numerical-Definitions.html#GDoubleIEEE754" title="union GDoubleIEEE754"><span class="type">GDoubleIEEE754</span></a> unions are used to access the sign, |
| mantissa and exponent of IEEE floats and doubles. These unions are defined |
| as appropriate for a given platform. IEEE floats and doubles are supported |
| (used for storage) by at least Intel, PPC and Sparc.</p> |
| <div class="refsect3"> |
| <a name="GDoubleIEEE754.members"></a><h4>Members</h4> |
| <div class="informaltable"><table class="informaltable" width="100%" border="0"> |
| <colgroup> |
| <col width="300px" class="union_members_name"> |
| <col class="union_members_description"> |
| <col width="200px" class="union_members_annotations"> |
| </colgroup> |
| <tbody><tr> |
| <td class="union_member_name"><p><a class="link" href="glib-Basic-Types.html#gdouble" title="gdouble"><span class="type">gdouble</span></a> <em class="structfield"><code><a name="GDoubleIEEE754.v-double"></a>v_double</code></em>;</p></td> |
| <td class="union_member_description"><p>the double value</p></td> |
| <td class="union_member_annotations"> </td> |
| </tr></tbody> |
| </table></div> |
| </div> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-E:CAPS"></a><h3>G_E</h3> |
| <pre class="programlisting">#define G_E 2.7182818284590452353602874713526624977572470937000 |
| </pre> |
| <p>The base of natural logarithms.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-LN2:CAPS"></a><h3>G_LN2</h3> |
| <pre class="programlisting">#define G_LN2 0.69314718055994530941723212145817656807550013436026 |
| </pre> |
| <p>The natural logarithm of 2.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-LN10:CAPS"></a><h3>G_LN10</h3> |
| <pre class="programlisting">#define G_LN10 2.3025850929940456840179914546843642076011014886288 |
| </pre> |
| <p>The natural logarithm of 10.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-PI:CAPS"></a><h3>G_PI</h3> |
| <pre class="programlisting">#define G_PI 3.1415926535897932384626433832795028841971693993751 |
| </pre> |
| <p>The value of pi (ratio of circle's circumference to its diameter).</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-PI-2:CAPS"></a><h3>G_PI_2</h3> |
| <pre class="programlisting">#define G_PI_2 1.5707963267948966192313216916397514420985846996876 |
| </pre> |
| <p>Pi divided by 2.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-PI-4:CAPS"></a><h3>G_PI_4</h3> |
| <pre class="programlisting">#define G_PI_4 0.78539816339744830961566084581987572104929234984378 |
| </pre> |
| <p>Pi divided by 4.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-SQRT2:CAPS"></a><h3>G_SQRT2</h3> |
| <pre class="programlisting">#define G_SQRT2 1.4142135623730950488016887242096980785696718753769 |
| </pre> |
| <p>The square root of two.</p> |
| </div> |
| <hr> |
| <div class="refsect2"> |
| <a name="G-LOG-2-BASE-10:CAPS"></a><h3>G_LOG_2_BASE_10</h3> |
| <pre class="programlisting">#define G_LOG_2_BASE_10 (0.30102999566398119521) |
| </pre> |
| <p>Multiplying the base 2 exponent by this number yields the base 10 exponent.</p> |
| </div> |
| </div> |
| </div> |
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