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| <h4 class="subsection">A.5.3 Floating Type Macros</h4> |
| |
| <p><a name="index-floating-type-measurements-3766"></a><a name="index-measurements-of-floating-types-3767"></a><a name="index-type-measurements_002c-floating-3768"></a><a name="index-limits_002c-floating-types-3769"></a> |
| The specific representation of floating point numbers varies from |
| machine to machine. Because floating point numbers are represented |
| internally as approximate quantities, algorithms for manipulating |
| floating point data often need to take account of the precise details of |
| the machine's floating point representation. |
| |
| <p>Some of the functions in the C library itself need this information; for |
| example, the algorithms for printing and reading floating point numbers |
| (see <a href="I_002fO-on-Streams.html#I_002fO-on-Streams">I/O on Streams</a>) and for calculating trigonometric and |
| irrational functions (see <a href="Mathematics.html#Mathematics">Mathematics</a>) use it to avoid round-off |
| error and loss of accuracy. User programs that implement numerical |
| analysis techniques also often need this information in order to |
| minimize or compute error bounds. |
| |
| <p>The header file <samp><span class="file">float.h</span></samp> describes the format used by your |
| machine. |
| |
| <ul class="menu"> |
| <li><a accesskey="1" href="Floating-Point-Concepts.html#Floating-Point-Concepts">Floating Point Concepts</a>: Definitions of terminology. |
| <li><a accesskey="2" href="Floating-Point-Parameters.html#Floating-Point-Parameters">Floating Point Parameters</a>: Details of specific macros. |
| <li><a accesskey="3" href="IEEE-Floating-Point.html#IEEE-Floating-Point">IEEE Floating Point</a>: The measurements for one common |
| representation. |
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