MPFR

Infobox_Software
name = MPFR



caption =
developer = INRIA and others
latest_release_version = 2.3.2
latest_release_date = September 12, 2008
operating_system = Cross-platform
genre = Mathematical software
license = LGPL
website = http://www.mpfr.org/

MPFR is a portable C library for arbitrary-precision binary floating-point computation with correct rounding, based on GNU Multi-Precision Library. The computation is both efficient and has a well-defined semantics. It copies the good ideas from the ANSI/IEEE-754 standard for fixed-precision floating-point arithmetic. More precisely, its main features are:
* Support for special numbers: signed zeros (Negative_zero), infinities and not-a-number (a single NaN is currently supported).
* Each number has its own precision (in bits since MPFR uses radix 2). The floating-point results are correctly rounded to the precision of the target variable, in any of the four IEEE-754 rounding modes.
* Supported functions: MPFR implements all mathematical functions from C99: the logarithm and exponential in natural base, base 2 and base 10, the log(1+x) and exp(x)-1 functions (log1p and expm1), the six trigonometric and hyperbolic functions and their inverses, the gamma, zeta and error functions, the arithmetic geometric mean, the power (x^y) function. All those functions are correctly rounded over their complete range.
* Subnormals are not supported, but can be emulated with the mpfr_subnormalize function.

MPFR is not able to track the accuracy of numbers in a whole program or expression; this is not its goal. Interval arithmetic packages like [http://mpfi.gforge.inria.fr/ MPFI] , or Real RAM implementations like [http://www.informatik.uni-trier.de/iRRAM/ iRRAM] , which may be based on MPFR, can do that for the user.

External links

* [http://www.mpfr.org/ Official MPFR web site]
* [https://gforge.inria.fr/projects/mpfr/ MPFR project page]