pyQuadp

Python interface to gcc's libquadmath for quad (128-bit) precision maths.

Build

python -m build
python -m pip install . 

Package is not yet available on pypi.

This package requires quadmath.h and libquadmath.so. This might come installed with your installation of gcc/gfortran from your package manager. Or it might require a separate installation. This should be installed before trying to install the Python package.

Fedora

sudo dnf install libquadmath libquadmath-devel

Usage

qfloat

A quad precision number is created by passing either a int, float, or string to qfloat:

import pyquadp

q = pyquadp.qfloat(1)
q = pyquadp.qfloat(1.0)
q = pyquadp.qfloat('1')

A qfloat implements Python's NumberProtocol, thus it can be used like any other number, either with basic math operations or in rich comparisons:

q1 = pyquadp.qfloat(1)
q2 = pyquadp.qfloat(2)

q1+q2 # pyquadp.qfloat(3)
q1*q2  # pyquadp.qfloat(2)
q1+=q2 # pyquadp.qfloat(3)

q1 <= q2 # True
q1 == q2 # False

str(q) # "1.000000000000000000000000000000000000e+00"

qcmplx

A quad precision number is created by passing either a complex variable or two ints, floats, strs, or qfloats to qcmplx:

import pyquadp

q = pyquadp.qcmplx(complex(1,1))
q = pyquadp.qcmplx(1,1.0)
q = pyquadp.qcmplx('1',1.0)
q = pyquadp.qcmplx('1','1')
q = pyquadp.qcmplx(pyquadp.qfloat(1), pyquadp.qfloat('1'))

Note that strings must be split into two components. There is no support for 1+1j (unless passed via complex('1+1j'))

Math libraries

The qmath provides the union of math operations from Python's math library and the routines provided in libquadmath. qmath provides routines for qfloat, while complex numbers are handled by qcmath versions.

Where possible functions accessed via the Python name follows Python's conventions regarding behavior of exceptional values. While routines from libquadmath (those ending in q) follows libquadmath's conventions.

Routines from Python's math library

Routines from gcc's libquadthmath library

Routines from Python's complex math cmath library

These are available from qcmath

Routines from complex math libquadthmath library

These are available from qcmath

Constants from libquadthmath library.

The following constants are availbe both in qmath and qcmath