diff --git a/.github/ISSUE_TEMPLATE.md b/.github/ISSUE_TEMPLATE.md
new file mode 100644
index 0000000..d9127d6
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE.md
@@ -0,0 +1,11 @@
+### Description
+
+Describe what you were trying to get done.
+Tell us what happened, what went wrong, and what you expected to happen.
+
+### What I Did
+
+```
+Paste the command(s) you ran and the output.
+If there was a crash, please include the traceback here.
+```
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
new file mode 100644
index 0000000..2642956
--- /dev/null
+++ b/.github/workflows/build_and_test.yml
@@ -0,0 +1,45 @@
+name: Build and Test
+
+on:
+    push:
+        branches: [ master, develop ]
+    pull_request:
+        branches: [ master, develop ]
+
+jobs:
+    build_linux:
+        name: "Build and test"
+        runs-on: ${{ matrix.os }}
+        strategy:
+            matrix:
+                os: [ubuntu-latest, windows-latest, macos-latest]
+                python-version: ["3.9", "3.10", "3.11", "3.12"]
+        steps:
+            -   uses: actions/checkout@v4
+            -   name: Set up Python ${{ matrix.python-version }}
+                uses: actions/setup-python@v5
+                with:
+                    python-version: ${{ matrix.python-version }}
+            -   name: Upgrade pip. setuptools and wheel
+                run: python -m pip install --upgrade pip setuptools wheel
+
+            -   name: Install development dependencies
+                run: pip install flake8 pytest pytest-cov
+            -   name: Lint with flake8
+                run: |
+                    # stop the build if there are Python syntax errors or undefined names
+                    flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+                    # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+                    flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+            -   name: Install package as editable
+                run: pip install -e .
+            -   name: Test with pytest
+                run: |
+                    pytest tests --junitxml=junit/test-results-${{ matrix.os }}-${{ matrix.python-version }}.xml --cov=com --cov-report=xml --cov-report=html
+            -   name: Upload pytest test results
+                uses: actions/upload-artifact@v4
+                with:
+                    name: pytest-results-${{ matrix.os }}-${{ matrix.python-version }}
+                    path: junit/test-results-${{ matrix.os }}-${{ matrix.python-version }}.xml
+                # Use always() to always run this step to publish test results when there are test failures
+                if: ${{ always() }}
diff --git a/.github/workflows/pypi-publish.yml b/.github/workflows/pypi-publish.yml
new file mode 100644
index 0000000..ce25ff7
--- /dev/null
+++ b/.github/workflows/pypi-publish.yml
@@ -0,0 +1,31 @@
+# This workflows will upload a Python Package using Twine when a release is created
+# For more information see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions#publishing-to-package-registries
+
+name: Upload Python Package
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  deploy:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.x'
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install setuptools wheel twine
+    - name: Build and publish
+      env:
+        TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
+        TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
+      run: |
+        python setup.py sdist bdist_wheel
+        twine upload dist/*
diff --git a/.gitignore b/.gitignore
index 6c92abd..49b36ee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -117,3 +117,6 @@ docs/_build/
 # PyBuilder
 target/
 
+# Environments
+.conda/
+.vscode/
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 1ab86a6..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,35 +0,0 @@
-language: python
-sudo: false
-python:
-  - 2.6
-  - 2.7
-  - 3.3
-  - 3.4
-  - 3.5
-  - "3.5-dev"
-  - "nightly"
-  - pypy
-matrix:
-  allow_failures:
-    - python: 2.6
-    - python: "3.5-dev"
-    - python: "nightly"
-    - python: pypy
-branches:
-  only:
-    - master
-    - develop
-addons:
-  apt:
-    packages:
-    - libblas-dev
-    - liblapack-dev
-    - libatlas-dev
-    - gfortran
-    - build-essential
-install:
-  - "pip install pytest pytest-cov python-coveralls"
-  - "travis_wait pip install -r requirements.txt"
-script: py.test tests/ --cov lspopt --cov-report term-missing
-after_success:
-  - coveralls
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..6fb5bb1
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,79 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [1.4.0] - 2025-01-07
+
+### Added
+
+- Support for Python 3.12
+- Support for `pip>=25`
+- Support for `numpy>=2`
+- Support for Windows and macOS
+
+### Removed
+
+- Support for Python 3.7 and 3.8
+- Unused imports
+
+
+## [1.3.0] - 2023-01-24
+
+### Changed
+
+- Modified test matrix in CI
+
+### Removed
+
+- Support for Python 2.7 and 3.6.
+- Dependency on `six`.
+
+
+## [1.2.0] - 2022-06-08
+
+### Added
+
+- New plot file
+
+### Fixed
+
+- Source distribution was broken on PyPI. Modified `MANIFEST.in` to correct that (#5 and #6)
+- Url to missing plot file
+- Fixed some incorrect int declarations using `1e3` notation
+
+### Removed
+
+- Removed Pipfile
+
+## [1.1.1] - 2020-09-28
+
+### Added
+
+- Added `CHANGELOG.md`
+
+### Changed
+
+- Change CI from Azure Devops to Github Actions
+
+
+## [1.1.0] - 2019-06-19
+
+### Added
+
+- First PyPI-released version
+
+
+## [1.0.0] - 2016-08-22
+
+### Added
+
+- Regarded as a feature-complete, stable library.
+
+
+[Unreleased]: https://github.com/hbldh/lspopt/compare/v1.3.0...HEAD
+[1.3.0]: https://github.com/hbldh/lspopt/compare/v1.2.0...v1.3.0
+[1.2.0]: https://github.com/hbldh/lspopt/compare/v1.1.1...v1.2.0
+[1.1.1]: https://github.com/hbldh/lspopt/compare/v1.1.0...v1.1.1
+[1.1.0]: https://github.com/hbldh/lspopt/compare/v1.0.0...v1.1.0
diff --git a/LICENSE b/LICENSE
index 8295bc7..03e60a3 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2015 Henrik Blidh
+Copyright (c) 2022 Henrik Blidh
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..63be52a
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,8 @@
+include LICENSE
+include README.md
+include HISTORY.md
+include requirements.txt
+include Pipfile
+include CHANGELOG.md
+include lspopt/data/c.npy
+include lspopt/data/weights.npy
diff --git a/README.md b/README.md
index 562b0e6..7ca5995 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,8 @@
 # LSPOpt
 
-[![Build Status](https://travis-ci.org/hbldh/lspopt.svg)](https://travis-ci.org/hbldh/lspopt)
-[![Coverage Status](https://coveralls.io/repos/github/hbldh/lspopt/badge.svg?branch=master)](https://coveralls.io/github/hbldh/lspopt?branch=master)
+![Build and Test](https://github.com/hbldh/lspopt/workflows/Build%20and%20Test/badge.svg)
+[![PyPI version](https://img.shields.io/pypi/v/lspopt.svg)](https://pypi.org/project/lspopt/)
+[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/ambv/black)
 
 This module is a Python implementation of the multitaper window method 
 described in [\[1\]](#references) for estimating Wigner spectra for certain locally
@@ -22,16 +23,17 @@ Abstract from [\[1\]](#references):
 
 Install via pip:
 
-    pip install git+https://github.com/hbldh/lspopt.git#egg=lspopt
+    pip install lspopt
+
+If you prefer to use `conda`, see [instructions in this repo](https://github.com/conda-forge/lspopt-feedstock).
 
 ## Testing
 
-Test with `nosetests`:
+Test with `pytest`:
 
-    nosetests tests/ 
+    pytest tests/
 
-Tests are run at every commit to GitHub and the results of this, as well as test 
-coverage, can be studied at [Travis CI](https://travis-ci.org/hbldh/lspopt).
+See test badge at the top of this README for link to test coverage and reports.
 
 ## Usage
 
@@ -39,7 +41,7 @@ To generate the taper windows only, use the `lspopt` method:
 
 ```python
 from lspopt import lspopt
-H, w = lspopt(N=256, c_parameter=20.0)
+H, w = lspopt(n=256, c_parameter=20.0)
 ```
     
 There is also a convenience method for using the [SciPy spectrogram method](https://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.spectrogram.html#scipy.signal.spectrogram)
@@ -64,13 +66,13 @@ import matplotlib.pyplot as plt
 
 from lspopt.lsp import spectrogram_lspopt
 
-fs = 10e3
-N = 1e5
+fs = 10000
+N = 100000
 amp = 2 * np.sqrt(2)
 noise_power = 0.001 * fs / 2
 time = np.arange(N) / fs
-freq = np.linspace(1e3, 2e3, N)
-x = amp * chirp(time, 1e3, 2.0, 6e3, method='quadratic') + \
+freq = np.linspace(1000, 2000, N)
+x = amp * chirp(time, 1000, 2.0, 6000, method='quadratic') + \
     np.random.normal(scale=np.sqrt(noise_power), size=time.shape)
 
 f, t, Sxx = spectrogram(x, fs)
@@ -87,14 +89,16 @@ ax.pcolormesh(t, f, Sxx)
 ax.set_ylabel('Frequency [Hz]')
 ax.set_xlabel('Time [sec]')
 
+plt.tight_layout()
 plt.show()
 ```
 
-![Spectrogram plot](https://hbldh.github.com/lspopt/images/plot.png)
+![Spectrogram plot](https://github.com/hbldh/lspopt/blob/master/plot.png "Top: Using SciPy's spectrogram method. Bottom: Using LSPOpt's spectrogram solution.")
+
 *Top: Using SciPy's spectrogram method. Bottom: Using LSPOpt's spectrogram solution.*
 
 ## References
 
 \[1\] [Hansson-Sandsten, M. (2011). Optimal multitaper Wigner spectrum 
 estimation of a class of locally stationary processes using Hermite functions. 
-EURASIP Journal on Advances in Signal Processing, 2011, 10.](http://asp.eurasipjournals.com/content/pdf/1687-6180-2011-980805.pdf)
+EURASIP Journal on Advances in Signal Processing, 2011, 10.](https://dx.doi.org/10.1155/2011/980805)
diff --git a/generate_plot.py b/generate_plot.py
index d7ea04e..37197f0 100644
--- a/generate_plot.py
+++ b/generate_plot.py
@@ -9,11 +9,6 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
 import six
 import numpy as np
 from scipy.signal import chirp, spectrogram
@@ -26,13 +21,13 @@
 
 
 def generate_chirp_spectrogram_plot():
-    fs = 10e3
-    N = 1e5
+    fs = 10000
+    N = 100000
     amp = 2 * np.sqrt(2)
     noise_power = 0.001 * fs / 2
     time = np.arange(N) / fs
-    freq = np.linspace(1e3, 2e3, N)
-    x = amp * chirp(time, 1e3, 2.0, 6e3, method='quadratic') + \
+    freq = np.linspace(1000, 2000, N)
+    x = amp * chirp(time, 1000, 2.0, 6000, method='quadratic') + \
         np.random.normal(scale=np.sqrt(noise_power), size=time.shape)
 
     f, t, Sxx = spectrogram(x, fs)
@@ -40,7 +35,7 @@ def generate_chirp_spectrogram_plot():
     ax = plt.subplot(211)
     ax.pcolormesh(t, f, Sxx)
     ax.set_ylabel('Frequency [Hz]')
-    ax.set_xlabel('Time [sec]')
+    ax.set_xlabel('Time [sec]', labelpad=10)
 
     f, t, Sxx = spectrogram_lspopt(x, fs, c_parameter=20.0)
 
@@ -49,6 +44,7 @@ def generate_chirp_spectrogram_plot():
     ax.set_ylabel('Frequency [Hz]')
     ax.set_xlabel('Time [sec]')
 
+    plt.tight_layout()
     plt.show()
 
 
@@ -100,11 +96,12 @@ def generate_lsp_processes_figures():
         ax.set_ylim([-1.5, 1.5])
         ax.set_xlabel('t')
 
+    plt.tight_layout()
     plt.show()
 
 
 def main():
-    #generate_chirp_spectrogram_plot()
+    generate_chirp_spectrogram_plot()
     generate_lsp_processes_figures()
 
 if __name__ == "__main__":
diff --git a/lspopt/__init__.py b/lspopt/__init__.py
index 7b4a19d..e507e97 100644
--- a/lspopt/__init__.py
+++ b/lspopt/__init__.py
@@ -1,69 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
+from lspopt.lsp import lspopt, spectrogram_lspopt
+from lspopt.__version__ import __version__, version
 
-try:
-    from lspopt.lsp import lspopt, spectrogram_lspopt
-    from tests.lspopt_ref import lspopt_ref
-    from lspopt import utils
-
-    __all__ = ['lspopt', 'spectrogram_lspopt', 'utils']
-except ImportError:
-    # We will end up here in installation case.
-    pass
-
-# Version information.  An empty _version_extra corresponds to a full
-# release.  'dev' as a _version_extra string means this is a development
-# version.
-_version_major = 1
-_version_minor = 0
-_version_patch = 0
-# _version_extra = 'dev1'
-# _version_extra = 'a6'
-_version_extra = ''  # Uncomment this for full releases
-
-# Construct full version string from these.
-_ver = [_version_major, _version_minor, _version_patch]
-
-__version__ = '.'.join(map(str, _ver))
-if _version_extra:
-    __version__ += _version_extra
-
-version = __version__  # backwards compatibility name
-version_info = (_version_major, _version_minor, _version_patch, _version_extra)
-
-__name__ = 'lspopt'
-__author__ = 'Henrik Blidh'
-__author_email__ = 'henrik.blidh@nedomkull.com'
-__maintainer__ = 'Henrik Blidh'
-__maintainer_email__ = 'henrik.blidh@nedomkull.com'
-__license__ = 'MIT'
-__description__ = "A Python implementation of a multitaper window method for " \
-                  "estimating Wigner spectra for certain locally stationary processes"
-__url__ = 'https://github.com/hbldh/lspopt'
-__download_url__ = 'https://github.com/hbldh/lspopt/tarball/' + '.'.join(map(str, _ver))
-__platforms__ = ['Linux', 'Mac OSX', 'Windows XP/Vista/7/8']
-__keywords__ = ['Mathmatical Statistics', 'Multitaper', 'Spectrogram']
-__classifiers__ = [
-                  'Development Status :: 5 - Production/Stable',
-                  'Intended Audience :: Science/Research',
-                  'Intended Audience :: Developers',
-                  'License :: MIT',
-                  'Topic :: Scientific/Engineering',
-                  'Operating System :: Microsoft :: Windows',
-                  'Operating System :: POSIX',
-                  'Operating System :: Unix',
-                  'Operating System :: MacOS',
-                  'Programming Language :: Python',
-                  'Programming Language :: Python :: 2',
-                  'Programming Language :: Python :: 2.6',
-                  'Programming Language :: Python :: 2.7',
-                  'Programming Language :: Python :: 3',
-                  'Programming Language :: Python :: 3.3',
-                  'Programming Language :: Python :: 3.4',
-                  'Programming Language :: Python :: 3.5',
-              ],
+__all__ = ["lspopt", "spectrogram_lspopt"]
diff --git a/lspopt/__version__.py b/lspopt/__version__.py
new file mode 100644
index 0000000..5add2d0
--- /dev/null
+++ b/lspopt/__version__.py
@@ -0,0 +1,5 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+version = "1.4.0"
+__version__ = version
diff --git a/lspopt/data/__init__.py b/lspopt/data/__init__.py
index 9d47c10..5726c28 100644
--- a/lspopt/data/__init__.py
+++ b/lspopt/data/__init__.py
@@ -8,22 +8,17 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
-from pkg_resources import resource_filename
+from importlib import resources
 
 import numpy as np
 
-__all__ = ['C', 'WEIGHTS', 'f_h']
+__all__ = ["C", "WEIGHTS", "f_h"]
 
 # An array of C parameter values for which weights have been pre-calculated.
-C = np.load(resource_filename('lspopt.data', 'c.npy')).flatten()
+C = np.load(resources.files("lspopt.data").joinpath("c.npy")).flatten()
 # The pre-calculated Hermite polynomial coefficients
 # for the C parameter values above.
-WEIGHTS = np.load(resource_filename('lspopt.data', 'weights.npy'))
+WEIGHTS = np.load(resources.files("lspopt.data").joinpath("weights.npy"))
 
 
 def f_h(n, k):
@@ -39,6 +34,7 @@ def f_h(n, k):
     """
     return n / _K_TO_VALUE_.get(k)
 
+
 # Given length of Hermite polynomial coefficient array, return
 # a value to divide N with.
 _K_TO_VALUE_ = {
@@ -51,5 +47,5 @@ def f_h(n, k):
     7: 9.8,
     8: 10.3,
     9: 10.9,
-    10: 11.2
+    10: 11.2,
 }
diff --git a/lspopt/lsp.py b/lspopt/lsp.py
index 49f6f44..8a24abc 100644
--- a/lspopt/lsp.py
+++ b/lspopt/lsp.py
@@ -14,12 +14,6 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
-import six
 import numpy as np
 from scipy.signal import spectrogram
 
@@ -60,19 +54,27 @@ def lspopt(n, c_parameter=20.0):
 
     t1 = np.arange(-(n / 2) + 1, (n / 2) + 0.1, step=1.0) / f_h(n, K)
     h = np.vstack((np.ones((n,)), 2 * t1))
-    for i in six.moves.range(1, K - 1):
+    for i in range(1, K - 1):
         h = np.vstack((h, (2 * t1 * h.T[:, i]) - 2 * i * h.T[:, i - 1]))
 
-    H = h.T * np.outer(np.exp(-(t1**2)/2), np.ones((K,), 'float'))
+    H = h.T * np.outer(np.exp(-(t1 ** 2) / 2), np.ones((K,), "float"))
     H /= np.array([np.linalg.norm(x) for x in H.T])
 
     return H.T.copy(), weights
 
 
-def spectrogram_lspopt(x, fs=1.0, c_parameter=20.0,
-                       nperseg=256, noverlap=None, nfft=None,
-                       detrend='constant', return_onesided=True,
-                       scaling='density', axis=-1):
+def spectrogram_lspopt(
+    x,
+    fs=1.0,
+    c_parameter=20.0,
+    nperseg=256,
+    noverlap=None,
+    nfft=None,
+    detrend="constant",
+    return_onesided=True,
+    scaling="density",
+    axis=-1,
+):
     """Convenience method for calling :py:meth:`scipy.signal.spectrogram` with
     :py:mod:`lspopt` multitaper windows.
 
@@ -144,15 +146,20 @@ def spectrogram_lspopt(x, fs=1.0, c_parameter=20.0,
     S_out = None
     # Call spectrogram method for each taper window.
     for taper_window, taper_weight in zip(H, taper_weights):
-        f, t, Pxx = spectrogram(x, fs=fs, window=taper_window,
-                                nperseg=nperseg, noverlap=noverlap,
-                                nfft=nfft, detrend=detrend,
-                                return_onesided=return_onesided,
-                                scaling=scaling, axis=axis)
+        f, t, Pxx = spectrogram(
+            x,
+            fs=fs,
+            window=taper_window,
+            nperseg=nperseg,
+            noverlap=noverlap,
+            nfft=nfft,
+            detrend=detrend,
+            return_onesided=return_onesided,
+            scaling=scaling,
+            axis=axis,
+        )
         if S_out is None:
             S_out = taper_weight * Pxx
         else:
             S_out += taper_weight * Pxx
     return f, t, S_out
-
-
diff --git a/lspopt/utils.py b/lspopt/utils.py
index 21a52d8..03cd37e 100644
--- a/lspopt/utils.py
+++ b/lspopt/utils.py
@@ -14,11 +14,6 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
 import numpy as np
 from scipy.linalg import sqrtm
 
@@ -93,7 +88,11 @@ def create_lscp_realisation(N, c, Fs, m, d, random_seed=None):
            EURASIP Journal on Advances in Signal Processing, 2011, 10.
 
     """
-    r_x = lambda a, b: _q((a + b) / 2) * _r(a - b, c) * np.exp(1j * m * (a - b) * ((a + b) / 2 - d))
+    r_x = (
+        lambda a, b: _q((a + b) / 2)
+        * _r(a - b, c)
+        * np.exp(1j * m * (a - b) * ((a + b) / 2 - d))
+    )
     return _create_realisation(r_x, N, Fs, random_seed)
 
 
@@ -135,13 +134,13 @@ def create_mlsp_realisation(N, c_vector, Fs, random_seed=None):
 
 def _create_realisation(r_x, N, Fs, random_seed):
     # Sampling vector.
-    t_vector = np.arange(-(N/2), N/2, 1) / Fs
+    t_vector = np.arange(-(N / 2), N / 2, 1) / Fs
 
     # Create real or complex matrix depending on covariance function output.
     if np.iscomplex(r_x(t_vector[0], t_vector[-1])):
-        Rx = np.zeros((N, N), 'complex')
+        Rx = np.zeros((N, N), "complex")
     else:
-        Rx = np.zeros((N, N), 'float')
+        Rx = np.zeros((N, N), "float")
 
     # Calculate covariance matrix.
     for i, t in enumerate(t_vector):
@@ -170,8 +169,8 @@ def _create_realisation(r_x, N, Fs, random_seed):
 
 
 def _q(tau):
-    return np.exp(-(tau ** 2)/2)
+    return np.exp(-(tau ** 2) / 2)
 
 
 def _r(tau, c):
-    return np.exp(-((c/4) * (tau ** 2)) / 2)
+    return np.exp(-((c / 4) * (tau ** 2)) / 2)
diff --git a/plot.png b/plot.png
new file mode 100644
index 0000000..b996901
Binary files /dev/null and b/plot.png differ
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..b3d5b86
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools >= 64", "wheel"]
+build-backend = "setuptools.build_meta"
diff --git a/requirements.txt b/requirements.txt
index fbbeba1..aae5d11 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,2 @@
-numpy>=1.6.2
-scipy>=0.16.1
-six>=1.10.0
+numpy>=1.21.6
+scipy>=1.7.3
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..d662cb9
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,5 @@
+[bdist_wheel]
+universal=1
+
+[aliases]
+test=pytest
diff --git a/setup.py b/setup.py
index d078c18..9a08fda 100644
--- a/setup.py
+++ b/setup.py
@@ -1,52 +1,124 @@
+#!/usr/bin/env python
 # -*- coding: utf-8 -*-
-"""
 
-Release data for the lspopt project.
+# Note: To use the 'upload' functionality of this file, you must:
+#   $ pip install twine
 
-Copyright (c) 2015, Nedomkull Mathematical Modeling AB.
-Created on 2015-11-15 by hbldh <henrik.blidh@nedomkull.com>
+import io
+import os
+import sys
+from shutil import rmtree
 
-"""
+from setuptools import find_packages, setup, Command
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import absolute_import
+# Package meta-data.
+NAME = 'lspopt'
+DESCRIPTION = "A Python implementation of a multitaper window method for " \
+              "estimating Wigner spectra for certain locally stationary processes"
+URL = 'https://github.com/hbldh/lspopt'
+EMAIL = 'henrik.blidh@gmail.com'
+AUTHOR = 'Henrik Blidh'
+REQUIRES_PYTHON = '>=3.9'
+VERSION = None
 
-import os
-from setuptools import setup, find_packages
+REQUIRED = [
+    'numpy>=1.21.6',
+    'scipy>=1.7.3',
+]
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+with io.open(os.path.join(here, 'README.md'), encoding='utf-8') as f:
+    long_description = '\n' + f.read()
+
+with io.open(os.path.join(here, 'CHANGELOG.md'), encoding='utf-8') as f:
+    long_description = long_description + '\n' + f.read()
+
+# Load the package's __version__.py module as a dictionary.
+about = {}
+if not VERSION:
+    with open(os.path.join(here, NAME, '__version__.py')) as f:
+        exec(f.read(), about)
+else:
+    about['__version__'] = VERSION
+
+
+class UploadCommand(Command):
+    """Support setup.py upload."""
+
+    description = 'Build and publish the package.'
+    user_options = []
 
-import lspopt
+    @staticmethod
+    def status(s):
+        """Prints things in bold."""
+        print('\033[1m{0}\033[0m'.format(s))
+
+    def initialize_options(self):
+        pass
+
+    def finalize_options(self):
+        pass
+
+    def run(self):
+        try:
+            self.status('Removing previous builds…')
+            rmtree(os.path.join(here, 'dist'))
+        except OSError:
+            pass
+
+        self.status('Building Source and Wheel (universal) distribution…')
+        os.system('{0} setup.py sdist bdist_wheel --universal'.format(sys.executable))
+
+        self.status('Uploading the package to PyPi via Twine…')
+        os.system('twine upload dist/*')
+
+        self.status('Pushing git tags…')
+        os.system('git tag v{0}'.format(about['__version__']))
+        os.system('git push --tags')
+        
+        sys.exit()
 
-basedir = os.path.dirname(os.path.abspath(__file__))
-with open(os.path.join(basedir, 'README.md')) as f:
-    LONG_DESCRIPTION = f.read()
 
 setup(
-    name='lspopt',
-    version=lspopt.__version__,
-    author=lspopt.__author__,
-    author_email=lspopt.__author_email__,
-    maintainer=lspopt.__maintainer__,
-    maintainer_email=lspopt.__maintainer_email__,
-    url=lspopt.__url__,
-    download_url=lspopt.__download_url__,
-    description=lspopt.__description__,
-    long_description=LONG_DESCRIPTION,
-    license=lspopt.__license__,
-    platforms=lspopt.__platforms__,
-    keywords=lspopt.__keywords__,
-    classifiers=lspopt.__classifiers__,
-    packages=find_packages(exclude=('tests', )),
+    name=NAME,
+    version=about['__version__'],
+    description=DESCRIPTION,
+    long_description=long_description,
+    long_description_content_type='text/markdown',
+    author=AUTHOR,
+    author_email=EMAIL,
+    python_requires=REQUIRES_PYTHON,
+    tests_require=['pytest', ],
+    url=URL,
+    keywords=['Mathematical Statistics', 'Multitaper', 'Spectrogram'],
+    packages=find_packages(exclude=('tests',)),
     package_data={
         'lspopt.data': ['*.npy']
     },
-    install_requires=[
-        'numpy>=1.6.2',
-        'scipy>=0.16.1',
-        'six>=1.10.0'
+    install_requires=REQUIRED,
+    include_package_data=True,
+    license='MIT',
+    classifiers=[
+        'Development Status :: 5 - Production/Stable',
+        'Intended Audience :: Science/Research',
+        'Intended Audience :: Developers',
+        'License :: OSI Approved :: MIT License',
+        'Topic :: Scientific/Engineering',
+        'Operating System :: Microsoft :: Windows',
+        'Operating System :: POSIX',
+        'Operating System :: Unix',
+        'Operating System :: MacOS',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy'
     ],
-    dependency_links=[],
-    ext_modules=[],
-    entry_points={}
+    # $ setup.py publish support.
+    cmdclass={
+        'upload': UploadCommand,
+    },
 )
-
diff --git a/tests/__init__.py b/tests/__init__.py
index 3b236f4..89072e0 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -1 +1 @@
-__author__ = 'hbldh'
+__author__ = "hbldh"
diff --git a/tests/lspopt_ref.py b/tests/lspopt_ref.py
index c59e8c9..5c2ab02 100644
--- a/tests/lspopt_ref.py
+++ b/tests/lspopt_ref.py
@@ -14,12 +14,6 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
-import six
 import numpy as np
 
 from lspopt.data import C, WEIGHTS
@@ -71,9 +65,9 @@ def lspopt_ref(n, c_parameter=20.0):
         if K > 2:
             for i in range(1, K - 1):
                 h = np.vstack((h, (2 * t1 * h.T[:, i]) - 2 * i * h.T[:, i - 1]))
-    H = h.T * np.outer(np.exp(-(t1**2)/2), np.ones((K,), 'float'))
+    H = h.T * np.outer(np.exp(-(t1 ** 2) / 2), np.ones((K,), "float"))
 
-    for i in six.moves.range(K):
+    for i in range(K):
         H[:, i] = H[:, i] / np.sqrt(H[:, i].T.dot(H[:, i]))  # Norm
 
     return H.T, wei
diff --git a/tests/test_implementation.py b/tests/test_implementation.py
index 93348bc..81550b9 100644
--- a/tests/test_implementation.py
+++ b/tests/test_implementation.py
@@ -14,15 +14,7 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
-import unittest
-
 import pytest
-import six
 import numpy as np
 from numpy.testing import assert_allclose
 from scipy.signal import chirp, spectrogram
@@ -31,7 +23,7 @@
 from .lspopt_ref import lspopt_ref
 
 
-@pytest.mark.parametrize("n", six.moves.range(64, 1024))
+@pytest.mark.parametrize("n", range(64, 1024))
 def test_different_n(n):
     """Test against reference implementation for different N."""
     h1, w1 = lspopt(n)
@@ -51,14 +43,15 @@ def test_different_c(c):
 
 def test_spectrogram_method():
     """Test the spectrogram method's functionality."""
-    fs = 10e3
-    N = 1e5
+    fs = 10000
+    N = 100000
     amp = 2 * np.sqrt(2)
     noise_power = 0.001 * fs / 2
     time = np.arange(N) / fs
-    freq = np.linspace(1e3, 2e3, N)
-    x = amp * chirp(time, 1e3, 2.0, 6e3, method='quadratic') + \
-        np.random.normal(scale=np.sqrt(noise_power), size=time.shape)
+    freq = np.linspace(1000, 2000, N)
+    x = amp * chirp(time, 1000, 2.0, 6000, method="quadratic") + np.random.normal(
+        scale=np.sqrt(noise_power), size=time.shape
+    )
 
     f, t, Sxx = spectrogram_lspopt(x, fs, c_parameter=20.0)
     f_sp, t_sp, Sxx_sp = spectrogram(x, fs)
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 3831ac1..c5e9817 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -14,22 +14,11 @@
 
 """
 
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-from __future__ import absolute_import
-
-import unittest
-
-import pytest
-import six
-import numpy as np
 from numpy.testing import assert_allclose
 
 from lspopt import utils
 
 
-
 def test_create_lsp_realisation():
     """Test that create method is working at least."""
     N = 256
@@ -56,7 +45,7 @@ def test_create_lscp_realisation():
 
 def test_create_mlsp_realisation():
     """Test that create method is working at least."""
-    N = 256 
+    N = 256
     c = [1.4, 20.0]
     Fs = 8.0
     x, H, Rx = utils.create_mlsp_realisation(N, c, Fs)