1<!-- ##### SECTION Title ##### --> 2Numerical Definitions 3 4<!-- ##### SECTION Short_Description ##### --> 5mathematical constants, and floating point decomposition 6 7<!-- ##### SECTION Long_Description ##### --> 8<para> 9GLib offers mathematical constants such as #G_PI for the value of pi; 10many platforms have these in the C library, but some don't, the GLib 11versions always exist. 12</para> 13 14<para> 15The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the 16 sign, mantissa and exponent of IEEE floats and doubles. These 17 unions are defined as appropriate for a given platform. 18 IEEE floats and doubles are supported (used for 19 storage) by at least Intel, PPC and Sparc, for reference: <ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 20</para> 21 22<!-- ##### SECTION See_Also ##### --> 23<para> 24<ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 25</para> 26 27<!-- ##### SECTION Stability_Level ##### --> 28 29 30<!-- ##### MACRO G_IEEE754_FLOAT_BIAS ##### --> 31<para> 32See <ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 33</para> 34 35 36 37<!-- ##### MACRO G_IEEE754_DOUBLE_BIAS ##### --> 38<para> 39See <ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 40</para> 41 42 43 44<!-- ##### UNION GFloatIEEE754 ##### --> 45<para> 46The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the 47 sign, mantissa and exponent of IEEE floats and doubles. These 48 unions are defined as appropriate for a given platform. 49 IEEE floats and doubles are supported (used for 50 storage) by at least Intel, PPC and Sparc, for reference: 51<ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 52</para> 53 54 55<!-- ##### UNION GDoubleIEEE754 ##### --> 56<para> 57The #GFloatIEEE754 and #GDoubleIEEE754 unions are used to access the 58 sign, mantissa and exponent of IEEE floats and doubles. These 59 unions are defined as appropriate for a given platform. 60 IEEE floats and doubles are supported (used for 61 storage) by at least Intel, PPC and Sparc, for reference: 62<ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 63</para> 64 65 66<!-- ##### MACRO G_E ##### --> 67<para> 68The base of natural logarithms. 69</para> 70 71 72 73<!-- ##### MACRO G_LN2 ##### --> 74<para> 75The natural logarithm of 2. 76</para> 77 78 79 80<!-- ##### MACRO G_LN10 ##### --> 81<para> 82The natural logarithm of 10. 83</para> 84 85 86 87<!-- ##### MACRO G_PI ##### --> 88<para> 89The value of pi (ratio of circle's circumference to its diameter). 90</para> 91 92 93 94<!-- ##### MACRO G_PI_2 ##### --> 95<para> 96Pi divided by 2. 97</para> 98 99 100 101<!-- ##### MACRO G_PI_4 ##### --> 102<para> 103Pi divided by 4. 104</para> 105 106 107 108<!-- ##### MACRO G_SQRT2 ##### --> 109<para> 110The square root of two. 111</para> 112 113 114 115<!-- ##### MACRO G_LOG_2_BASE_10 ##### --> 116<para> 117Used for fooling around with float formats, see 118<ulink url="http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html">http://cch.loria.fr/documentation/IEEE754/numerical_comp_guide/ncg_math.doc.html</ulink> 119</para> 120 121 122 123