A library for the calculation of hafnians, Hermite polynomials and Gaussian boson sampling.
Adds the function find_classical_subsystem that tries to find a subset of the modes with a classical covariance matrix. #193
Adds the functions mean_number_of_clicks and variance_number_of_clicks that calculate the first and second statistical moments of the total number of clicks in a Gaussian state centered at the origin. #195
Adds the module decompositions with the function williamson to find the Williamson decomposition of an even-size positive-semidefinite matrix. #200
Adds the loop_hafnian_quad function to the Python interface for converting double precision matrices into quad precision, doing the calculations in quad precision, and then return the result as a double. #201
Introduces a new faster and significantly more accurate algorithm to calculate power traces allowing to speed up the calculation of loop hafnians #199
The quantum module has been refactored and organized into sub-modules. Several functions have been renamed, while the old names are being deprecated. #197
Adds support for C++14 #202
pytest-randomly is added to the test suite to improve testing and avoid stochastically failing tests. #205
Modifies the function input_validation to use np.allclose for checking the symmetry of the input matrices. #206
Modifies the function _hafnian to calculate efficiently loop hafnians of diagonal matrices. #206
Removes the redundant function normal_ordered_complex_cov. #194
Renames the function mean_number_of_clicks to be mean_number_of_click_graph. #195
This release contains contributions from (in alphabetical order):
Theodor Isacsson, Nicolas Quesada, Trevor Vincent
Adds a new algorithm for hafnians of matrices with low rank. #166
Adds a function to calculate the fidelity between two Gaussian quantum states. #169
Adds a new module, thewalrus.random, to generate random unitary, symplectic and covariance matrices. #169
Adds new functions normal_ordered_expectation, photon_number_expectation and photon_number_squared_expectation in thewalrus.quantum to calculate expectation values of products of normal ordered expressions and number operators and their squares. #175
Adds the function hafnian_sample_graph_rank_one in thewalrus.samples to sample from rank-one adjacency matrices. #174
Adds parallelization support using Dask for quantum.probabilities. #161
Removes support for Python 3.5. #163
Changes in the interface and speed ups in the functions in the thewalrus.fock_gradients module. #164
Improves documentation of the multidimensional Hermite polynomials. #166
Improves speed of fock_tensor when the symplectic matrix passed is also orthogonal. #166
Fixes Numba decorated functions not rendering properly in the documentation. #173
Solves the issue with quantum and samples not being rendered in the documentation or the TOC. #173
Fix bug where quantum and samples were not showing up in the documentation. #182
thewalrus.fock_gradients are now separated into functions for the gradients and the gates. Moreover, they are renamed, for instance Dgate becomes displacement and its gradient is now grad_displacement. #164
This release contains contributions from (in alphabetical order):
Theodor Isacsson, Josh Izaac, Filippo Miatto, Nicolas Quesada
Adds a new algorithm for hafnians of matrices with low rank. #166
Adds a function to calculate the fidelity between two Gaussian quantum states. #169
Adds a new module, thewalrus.random, to generate random unitary, symplectic and covariance matrices. #169
Adds new functions normal_ordered_expectation, photon_number_expectation and photon_number_squared_expectation in thewalrus.quantum to calculate expectation values of products of normal ordered expressions and number operators and their squares. #175
Adds the function hafnian_sample_graph_rank_one in thewalrus.samples to sample from rank-one adjacency matrices. #174
Adds parallelization support using Dask for quantum.probabilities. #161
Removes support for Python 3.5. #163
Changes in the interface and speed ups in the functions in the thewalrus.fock_gradients module. #164
Improves documentation of the multidimensional Hermite polynomials. #166
Improves speed of fock_tensor when the symplectic matrix passed is also orthogonal. #166
Fixes Numba decorated functions not rendering properly in the documentation. #173
Solves the issue with quantum and samples not being rendered in the documentation or the TOC. #173
thewalrus.fock_gradients are now separated into functions for the gradients and the gates. Moreover, they are renamed, for instance Dgate becomes displacement and its gradient is now grad_displacement. #164
This release contains contributions from (in alphabetical order):
Theodor Isacsson, Filippo Miatto, Nicolas Quesada
Adds the ability to calculate the mean number of photons in a given mode of a Gaussian state. #148
Adds the ability to calculate the photon number distribution of a pure or mixed state using generate_probabilities. #152
Allows to update the photon number distribution when undergoing loss by using update_probabilities_with_loss. #152
Allows to update the photon number distribution when undergoing noise update_probabilities_with_noise. #153
Adds a brute force sampler photon_number_sampler that given a (multi-)mode photon number distribution generates photon number samples. #152
Adds the ability to perform the Autonne-Takagi decomposition of a complex-symmetric matrix using autonne from the symplectic module. #154
Improves the efficiency of Hermite polynomial calculation in hermite_multidimensional.hpp. #141
Implements parallelization with Dask for sampling from the Hafnian/Torontonian of a Gaussian state. #145
state_vector, pure_state_amplitude, and density_matrix_element #149
This release contains contributions from (in alphabetical order):
Theodor Isacsson, Nicolas Quesada, Kieran Wilkinson
Introduces the renormalized hermite polynomials. These new polynomials improve the speed and accuracy of thewalrus.quantum.state_vector and thewalrus.quantum.density_matrix and also hafnian_batched and hermite_multimensional when called with the optional argument renorm=True. #108
Adds functions for calculating the covariance for the photon number distribution of a Gaussian state including a function for the full covariance matrix. #137
Adds support for Python 3.8. #138
Updates the reference that should be used when citing The Walrus. #102
Updates and improves the speed and accuracy of thewalrus.quantum.fock_tensor. #107
Add OpenMP support to the repeated moment hafnian code. #120
Improves speed of the functions in hermite_multidimensional.hpp. #123
Improves speed of the functions in thewalrus.fock_gradients by doing calls to optimized functions in hermite_multidimensional.hpp. #123
Further improves speed of the functions thewalrus.fock_gradients by writing explicit recursion relations for a given number of modes. #129
Adds the functions find_scaling_adjacency_matrix_torontonian and mean_number_of_clicks that allow to fix the mean number of clicks when doing threshold detection sampling and allow to calculate the mean of clicks generated by a scaled adjacency matrix. #136
Corrects typos in the random number generation in the C++ unit tests. #118
Corrects typos in describing the repeated-moment algorithm of Kan in the documentation. #104
Removes paper.{md,pdf,bib} from the repository now that The Walrus paper is published in Journal of Open Source Software #106
Updates the S2gate to use the correct definition. #130
Corrects the issue with hbar taking a default value when calculating mu in the density matrix function #134
This release contains contributions from (in alphabetical order):
Theodor Isacsson, Josh Izaac, Filippo Miatto, Nicolas Quesada, Trevor Vincent, Kieran Wilkinson
Small release to add a DOI on Zenodo.
Adds the function thewalrus.quantum.fock_tensor that returns the Fock space tensor corresponding to a Symplectic transformation in phase space. #90
Adds the thewalrus.fock_gradients module which provides the Fock representation of a set of continuous-variable universal gates in the Fock representation and their gradients. #96
Unifies return values of all symplectic gates in the thewalrus.symplectic module. #81
Removes unnecessary citations in the tutorials. #92
Improves the efficiency of the multidimensional Hermite polynomials implementation and simplifies a number of derived functions. #93
thewalrus.quantum.state_vector. This bug was found and fixed while implementing thewalrus.quantum.fock_tensor. #90
This release contains contributions from (in alphabetical order):
Josh Izaac, Nicolas Quesada
symplectic which allows easy access to symplectic transformations and covariance matrices of Gaussian states. #78
thewalrus.quantum.density_matrix.This release contains contributions from (in alphabetical order):
Josh Izaac, Nicolas Quesada
Adds classical sampling of permanents of positive definite matrices in csamples. #61
The Walrus gallery with examples of nongaussian state preparations that can be studied using the functions from the quantum module. #55
Important bugfix in quantum. This bug was detected by running the tests in test_integration. #48
Corrects the Makefile so that it uses the environment variable pointing to Eigen (if available). #58
Removes any reference to Fortran in the Makefile. #58
This release contains contributions from (in alphabetical order):
Luke Helt, Josh Izaac, Soran Jahangiri, Nicolas Quesada, Guillaume Thekkadath
Hafnian library has been renamed to The Walrus, and the low-level libhafnian C++ library renamed to libwalrus. #34
Added a seed function thewalrus.samples.seed, in order to make the sampling algorithms deterministic for testing purposes. #29
Added support for the batched hafnian; hafnian_batched (in Python) and libwalrus::hermite_multidimensional_cpp (in C++). This is a newly added algorithm that allows a batch of photon number statistics to be computed for a given quantum Gaussian state. #21
Adds the ability to sample from Gaussian states with finite means. #25
Permanent Fortran code was ported to C++, with improvements including support for quadruple precision and summation using the fsum algorithm. #20
Reorganization of the repository structure; C++ source code folder has been renamed from src to include, C++ tests have been moved into their own top-level directory tests, and the hafnian/lib subpackage has been removed in favour of a top-level thewalrus/libwalrus.so module. #34
Added additional references to the bibliography #30
Adds documentation related to permanents, sampling states with nonzero displacement, sampling of classical states, and multidimensional Hermite polynomials and batched hafnians. #27
Simplifies the hafnian sampling functions #25
Test improvements, including replacing custom tolerance checks with np.allclose(). #23
This release contains contributions from (in alphabetical order):
Brajesh Gupt, Josh Izaac, Nicolas Quesada