diff options
author | Hanna Mendes Levitin <hanna@anomaly-3.local> | 2010-12-01 03:37:07 -0600 |
---|---|---|
committer | Hanna Mendes Levitin <hanna@anomaly-3.local> | 2010-12-01 03:37:07 -0600 |
commit | a0549b4a15a7093f990fffa4bc1d2d52ec1c16e2 (patch) | |
tree | 9c6383570be6d045db4d8942ca3137fc3cb5b8a0 /docs/source/lang/cpp/double.rst | |
parent | 3b7f16dba295da3a0071564ac284c25dc56e6b18 (diff) | |
download | librambutan-a0549b4a15a7093f990fffa4bc1d2d52ec1c16e2.tar.gz librambutan-a0549b4a15a7093f990fffa4bc1d2d52ec1c16e2.zip |
docs, now with style
Diffstat (limited to 'docs/source/lang/cpp/double.rst')
-rw-r--r-- | docs/source/lang/cpp/double.rst | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/docs/source/lang/cpp/double.rst b/docs/source/lang/cpp/double.rst new file mode 100644 index 0000000..1527778 --- /dev/null +++ b/docs/source/lang/cpp/double.rst @@ -0,0 +1,48 @@ +.. _lang-double: + +``double`` +========== + +Double precision floating point type. Occupies 8 bytes. On Maple, the +``double`` type has a range of approximately -1.79769×10^308 to +1.79769×10^308; the ``double`` type subject to the same :ref:`overflow +issues <lang-variables-rollover>` as any numeric data type. + +Floating point numbers are not exact, and may yield strange results +when compared. For example ``6.0 / 3.0`` may not equal ``2.0``. You +should instead check that the absolute value of the difference between +the numbers is less than some small number. + +Floating point math is also much slower than integer math in +performing calculations, so should be avoided if, for example, a loop +has to run at top speed for a critical timing function. Programmers +often go to some lengths to convert floating point calculations to +integer math to increase speed. + +For more information, see the `Wikipedia article on floating point +math <http://en.wikipedia.org/wiki/Floating_point>`_\ . + +Floating-point numbers represent numbers with "decimal point", unlike +integral types, which always represent whole numbers. Floating-point +numbers are often used to approximate analog and continuous values +because they have greater resolution than integers. + +The double implementation on the Maple uses twice the number of bytes +as a :ref:`float <lang-float>`, with the corresponding gains in +precision. + +Tip +--- + +Users who borrow code from other sources that includes ``double`` +variables may wish to examine the code to see if the implied range and +precision are different from that actually achieved on the Maple. + +See Also +-------- + +- :ref:`float <lang-float>` + + + +.. include:: cc-attribution.txt |