Welcome to QformatPy documentation!

Introduction

Welcome to the qformat Python library, a powerful tool for formatting floating-point numbers into fixed-point representation with Q notation.

This library supports ARM’s Q format, where QI includes the sign bit.

The main function, qformat, allows users to specify the number of integer bits (QI), fractional bits (QF), whether the number is signed or unsigned, and provides flexibility in choosing rounding and overflow handling methods.

Whether you’re working on embedded systems, signal processing, or any application requiring fixed-point representation, qformat is here to streamline the process.

The example below shows pi being converter to the sQ4.8 format, using Truncation as the rounding method:

>>> from qformatpy import qformat

>>> x = 3.141592653589793
>>> result = qformat(x, qi=4, qf=8, rnd_method='Trunc')
>>> result
array([3.140625])

Installation

The qformatpy library is available via PIP install:

python3 -m venv pyenv
source pyenv/bin/activate

pip install qformatpy

Import the package as shown below:

import qformatpy

The following functions should be available:

A brief description of the functions can be seen below:

overflow(iarray, signed, w, overflow_action)

Handle overflow in an integer array based on the specified overflow action.

rounding(iarray, rnd_method)

Rounds each element in the input array according to the specified rounding method.

qformat(x, qi, qf[, signed, rnd_method, ...])

Format a given numeric value 'x' into fixed-point representation with Q format.

Example usage

>>> import numpy as np
>>> import qformatpy

>>> test_array = np.array([1.4, 5.57, 3.14])
>>> qformatpy.rounding(test_array, 'TowardsZero')
array([1, 5, 3])

>>> qformatpy.rounding(test_array, 'HalfDown')
array([1, 6, 3])