Setting up mpmath¶
Download and installation¶
The mpmath setup files can be downloaded from the Python Package Index. Download the source package (available as both .zip and .tar.gz), extract it, open the extracted directory, and run
python setup.py install
Releases are registered on PyPI, so you can install latest release of the Mpmath with pip
pip install mpmath
or some specific version with
pip install mpmath==0.19
If you have setuptools installed, you can download and install mpmath in one step by running:
python -m easy_install mpmath
If you have an old version of mpmath installed already, you may have to pass
-U flag to force an upgrade.
If installation fails, try deleting the following folders: .eggs, mpmath.egg-info, dist, build
Debian and Ubuntu users can install mpmath with
sudo apt-get install python-mpmath
Mpmath is provided in the “Science” repository for all recent versions of openSUSE. To add this repository to the YAST software management tool, see http://en.opensuse.org/SDB:Add_package_repositories
Look up http://download.opensuse.org/repositories/science/ for a list of supported OpenSUSE versions and use http://download.opensuse.org/repositories/science/openSUSE_11.1/ (or accordingly for your OpenSUSE version) as the repository URL for YAST.
Checking that it works¶
After the setup has completed, you should be able to fire up the interactive Python interpreter and do the following:
>>> from mpmath import * >>> mp.dps = 50 >>> print(mpf(2) ** mpf('0.5')) 1.4142135623730950488016887242096980785696718753769 >>> print(2*pi) 6.2831853071795864769252867665590057683943387987502
Note: if you have are upgrading mpmath from an earlier version, you may have to manually uninstall the old version or remove the old files.
Using gmpy (optional)¶
By default, mpmath uses Python integers internally. If gmpy version 1.03 or later is installed on your system, mpmath will automatically detect it and transparently use gmpy integers intead. This makes mpmath much faster, especially at high precision (approximately above 100 digits).
To verify that mpmath uses gmpy, check the internal variable
BACKEND is not equal to ‘python’:
>>> import mpmath.libmp >>> mpmath.libmp.BACKEND 'gmpy'
The gmpy mode can be disabled by setting the MPMATH_NOGMPY environment variable. Note that the mode cannot be switched during runtime; mpmath must be re-imported for this change to take effect.
It is recommended that you run mpmath’s full set of unit tests to make sure everything works. The py.test is a required dependence for testing. The tests are located in the
tests subdirectory of the main mpmath directory. They can be run using:
``py.test --pyargs mpmath``
If any test fails, please send a detailed bug report to the mpmath issue tracker.
To run the tests with support for gmpy disabled, set
MPMATH_NOGMPY environment variable.
To enable extra diagnostics, use, set
MPMATH_STRICT environment variable.
Compiling the documentation¶
If you downloaded the source package, the text source for these documentation pages is included in the
doc directory. The documentation can be compiled to pretty HTML using Sphinx. Go to the
doc directory and run
You can also test that all the interactive examples in the documentation work by running
and by running the individual
.py files in the mpmath source.
(The doctests may take several minutes.)
Finally, some additional demo scripts are available in the
demo directory included in the source package.
Mpmath under Sage¶
Mpmath is a standard package in Sage, in version 4.1 or later of Sage. Mpmath is preinstalled a regular Python module, and can be imported as usual within Sage:
---------------------------------------------------------------------- | Sage Version 4.1, Release Date: 2009-07-09 | | Type notebook() for the GUI, and license() for information. | ---------------------------------------------------------------------- sage: import mpmath sage: mpmath.mp.dps = 50 sage: print mpmath.mpf(2) ** 0.5 1.4142135623730950488016887242096980785696718753769
The mpmath installation under Sage automatically use Sage integers for asymptotically fast arithmetic, so there is no need to install GMPY:
sage: mpmath.libmp.BACKEND 'sage'
In Sage, mpmath can alternatively be imported via the interface library
sage.libs.mpmath.all. For example:
sage: import sage.libs.mpmath.all as mpmath
This module provides a few extra conversion functions, including
which permits calling any mpmath function with Sage numbers as input, and getting
with the appropriate precision back:
sage: w = mpmath.call(mpmath.erf, 2+3*I, prec=100) sage: w -20.829461427614568389103088452 + 8.6873182714701631444280787545*I sage: type(w) <type 'sage.rings.complex_number.ComplexNumber'> sage: w.prec() 100
See the help for
sage.libs.mpmath.all for further information.