• Added cuda engine to pylops.waveeqprocessing.Kirchhoff operator
• Added Opbasis and optimal_coeff to pylops.optimization.cls_sparsity.OMP
• Added solver to the input parameters of the _oneshot internal methods of pylops.waveeqprocessing.AcousticWave2D to avoid recreating it for every shot
• Added kwargs_fft to pylops.signalprocessing.FFT, pylops.signalprocessing.FFT2D, and pylops.signalprocessing.FFTND
• Fix bug in pylops.waveeqprocessing.MDD when using CuPy arrays for G and d with twosided=True and add_negative=True
• Fix bug in pylops.signalprocessing.FourierRadon3D in the default choice of num_threads_per_blocks
• Fix bug in pylops.signalprocessing.Convolve1D in the definition of pad and padd when applying the operator to a CuPy array
• Fix bug in pylops.optimization.cls_sparsity.OMP avoiding passing explicit in the creation of _ColumnLinearOperator
• Fix bug in pylops.optimization.cls_sparsity.OMP callback method as cols was not passed not allowing x to be properly reconstructed
• Fix bug in pylops.waveeqprocessing.SeismicInterpolation in calculation of sampling when not passed

• Added pylops.signalprocessing.FourierRadon2d and
  pylops.signalprocessing.FourierRadon3d operators
• Added pylops.PyTensorOperator operator
• Added pylops.ToCupy operator
• Added pylops.utils.seismicevents.parabolic3d method
• Fix bug in pylops.Restriction when passing iava as cupy array

• Fixed bug in pylops.utils.backend (see Issue #606)

• Added pylops.JaxOperator, pylops.signalprocessing.DWTND, and pylops.signalprocessing.DTCWT operators.
• Added updatesrc method to pylops.waveeqprocessing.AcousticWave2D.
• Added verb to pylops.signalprocessing.Sliding1D.sliding1d_design, pylops.signalprocessing.Sliding2D.sliding2d_design, pylops.signalprocessing.Sliding3D.sliding3d_design, pylops.signalprocessing.Patch2D.patch2d_design, and pylops.signalprocessing.Patch3D.patch3d_design.
• Added kwargs_fft to pylops.signalprocessing.FFTND.
• Added cosinetaper to pylops.utils.tapers.cosinetaper.
• Added kind to pylops.waveeqprocessing.Deghosting.
• Modified all methods in pylops.utils.backend to enable jax integration.
• Modified implementations of pylops.signalprocessing.Sliding1D, pylops.signalprocessing.Sliding2D,
  pylops.signalprocessing.Sliding3D, pylops.signalprocessing.Patch2D, and
  pylops.signalprocessing.Patch3D to being directly implemented instead of relying on other PyLops operators. Added also savetaper parameter and an option to apply the operator Op simultaneously to all windows.
• Modified pylops.waveeqprocessing.AcousticWave2D._born_oneshot and
  pylops.waveeqprocessing.AcousticWave2D._born_allshots to avoid recreating the devito solver for each shot (and enabling internal caching...)
• Modified dtype of pylops.signalprocessing.Shift to be that of the input vector.
• Modified pylops.waveeqprocessing.BlendingContinuous to use matvec/rmatvec instead of @/.H @ for compatibility with pylops solvers.
• Removed cusignal as optional dependency and cupy's equivalent methods (since the library
  is now unmantained and merged into cupy).
• Fixed ImportError of optional dependencies when installed but not correctly functioning (see Issue #548)
• Fixed bug in :py:func:pylops.utils.deps.to_cupy_conditional (see Issue #579)
• Fixed bug in the definition of nttot in :py:class:pylops.waveeqprocessing.BlendingContinuous
• Fixed bug in :py:func:pylops.utils.signalprocessing.dip_estimate (see Issue #572)

• Added pylops.signalprocessing.NonStationaryConvolve3D operator
• Added nd-array capabilities to pylops.basicoperators.Identity and pylops.basicoperators.Zero
• Added second implementation in pylops.waveeqprocessing.BlendingContinuous which is more
  performant when dealing with small number of receivers
• Added forceflat property to operators with ambiguous rmatvec (pylops.basicoperators.Block,
  pylops.basicoperators.Bilinear, pylops.basicoperators.BlockDiag, pylops.basicoperators.HStack,
  pylops.basicoperators.MatrixMult, pylops.basicoperators.VStack, and pylops.basicoperators.Zero)
• Improved dynamic mode of pylops.waveeqprocessing.Kirchhoff operator
• Modified pylops.signalprocessing.Convolve1D to allow both filters that are both shorter and longer of the
  input vector
• Modified all solvers to use matvec/rmatvec instead of @/.H @ to improve performance

• Added pylops.signalprocessing.DCT, pylops.signalprocessing.NonStationaryConvolve1D,
  pylops.signalprocessing.NonStationaryConvolve2D, pylops.signalprocessing.NonStationaryFilters1D, and
  pylops.signalprocessing.NonStationaryFilters2D operators
• Added pylops.waveeqprocessing.BlendingContinuous, pylops.waveeqprocessing.BlendingGroup, and
  pylops.waveeqprocessing.BlendingHalf operators
• Added kind='datamodel' to pylops.optimization.cls_sparsity.IRLS
• Improved inner working of pylops.waveeqprocessing.Kirchhoff operator significantly
  reducing the memory usage related to storing traveltime, angle, and amplitude tables.
• Improved handling of haxes in pylops.signalprocessing.Radon2D and pylops.signalprocessing.Radon3D operators
• Added possibility to feed ND-arrays to pylops.TorchOperator
• Removed pylops.LinearOperator inheritance and added __call__ method to pylops.TorchOperator
• Removed scipy.sparse.linalg.LinearOperator and added abc.ABC inheritance to pylops.LinearOperator
• All operators are now classes of pylops.LinearOperator type

PyLops has undergone significant changes in this release, including new LinearOperators, more features, new examples and bugfixes.
To aid users in navigating the breaking changes, we provide the following document MIGRATION_V1_V2.md.

New Features

• Multiplication of linear operators by N-dimensional arrays is now supported via the new dims/dimsd properties.
  Users do not need to use .ravel and .reshape as often anymore. See the migration guide for more information.
• Typing annotations for several submodules (avo, basicoperators, signalprocessing, utils, optimization, waveeqprocessing)
• New pylops.TorchOperator wraps a Pylops operator into a PyTorch function
• New pylops.signalprocessing.Patch3D applies a linear operator repeatedly to patches of the model vector
• Each of Sliding1D, Sliding2D, Sliding3D, Patch2D and Patch3D have an associated slidingXd_design or patchXd_design functions associated with them to aid the user in designing the windows
• FirstDerivative and SecondDerivative, and therefore other derivative operators which rely on the (e.g., Gradient) support higher order stencils
• pylops.waveeqprocessing.Kirchhoff substitutes pylops.waveeqprocessing.Demigration and incorporates a variety of new functionalities
• New pylops.waveeqprocessing.AcousticWave2D wraps the Devito acoutic wave propagator providing a wave-equation based Born modeling operator with a reverse-time migration adjoint
• Solvers can now be implemented via the pylops.optimization.basesolver.Solver class. They can now be used through a functional interface with lowercase name (e.g., splitbregman) or via class interface with CamelCase name (e.g., SplitBregman). Moreover, solvers now accept callbacks defined by the Callbacks interface (see e.g., MetricsCallback).
• Metrics such as mean absolute error (mae), mean squared error (mse) and others
• New pylops.utils.signalprocessing.dip_estimate estimates local dips in an image (measured in radians) in a stabler way than pylops.utils.signalprocessing.dip_estimate did for slopes.
• New pylops.utils.tapers.tapernd for N dimensional tapers
• New wavelets Klauder and Ormsby

Documentation

• Installation has been revamped
• Revamped guide on how to implement a new LinearOperator from scratch
• New guide on how to implement a new solver from scratch
• New tutorials:
  • Solvers (Advanced)
  • Deblending
  • Automatic Differentiation
• New gallery examples:
  • Patching
  • Wavelets

• Fixed pylops.optimization.basic.lsqr, pylops.optimization.sparsity.ISTA, and
  pylops.optimization.sparsity.FISTA to work with cupy arrays. This change was required
  by how recent cupy versions handle scalars, which are not converted directly into float types,
  rather kept as cupy arrays.
• Fixed bug in pylops.waveeqprocessing.Deghosting introduced in
  commit 7e596d4

• Added NMO example to gallery
• Extended pylops.basicoperators.Laplacian to N-dimensional arrays
• Added forward kind to pylops.basicoperators.SecondDerivative and
  pylops.basicoperators.Laplacian
• Added chirp-sliding kind to pylops.waveeqprocessing.seismicinterpolation.SeismicInterpolation
• Fixed bug due to the new internal structure of LinearOperator submodule introduced in scipy1.8.0

• Added NMO example to gallery
• Extended pylops.basicoperators.Laplacian to N-dimensional arrays
• Added forward kind to pylops.basicoperators.SecondDerivative and
  pylops.basicoperators.Laplacian
• Added chirp-sliding kind to pylops.waveeqprocessing.seismicinterpolation.SeismicInterpolation
• Fixed bug due to the new internal structure of LinearOperator submodule introduced in scipy1.8.0