v1.16.0

• Added pylops.utils.estimators module for trace estimation
• Added x0 in pylops.optimization.sparsity.ISTA and
  pylops.optimization.sparsity.FISTA to handle non-zero initial guess
• Modified pylops.optimization.sparsity.ISTA and
  pylops.optimization.sparsity.FISTA to handle multiple right hand sides
• Modified creation of haxis in pylops.signalprocessing.Radon2D and
  pylops.signalprocessing.Radon3D to allow for uncentered spatial axes
• Fixed _rmatvec for explicit in pylops.LinearOperator._ColumnLinearOperator

v1.15.0

• Added pylops.signalprocessing.Shift operator.
• Added option to choose derivative kind in
  pylops.avo.poststack.PoststackInversion and
  pylops.avo.prestack.PrestackInversion
• Improved efficiency of adjoint of
  pylops.signalprocessing.Fredholm1 by applying complex conjugation
  to the vectors.
• Added vsvp to pylops.avo.prestack.PrestackInversion allowing
  to use user defined VS/VP ratio.
• Added kind to pylops.basicoperators.CausalIntegration allowing
  full, half, or trapezoidal integration
• Fixed _hardthreshold_percentile in
  pylops.optimization.sparsity - Issue #249.
• Fixed r2norm in pylops.optimization.solver.cgls

v1.14.0

• Added pylops.optimization.solver.lsqr solver
• Added utility routine pylops.utils.scalability_test for scalability
  tests when using multiprocessing
• Added pylops.avo.avo.ps AVO modelling option and restructured
  pylops.avo.prestack.PrestackLinearModelling to allow passing any
  function handle that can perform AVO modelling apart from those directly
  available
• Added R-linear operators (when setting the property clinear=False of a
  linear operator). pylops.basicoperators.Real,
  pylops.basicoperators.Imag, and pylops.basicoperators.Conj
• Added possibility to run operators pylops.basicoperators.HStack,
  pylops.basicoperators.VStack, pylops.basicoperators.Block
pylops.basicoperators.BlockDiag,
  and pylops.signalprocessing.Sliding3D using multiprocessing
• Added dtype to vector X when using scipy.sparse.linalg.lobpcg in
  eigs method of pylops.LinearOperator
• Use kind=forward fot FirstDerivative in
  pylops.avo.poststack.PoststackInversion inversion when dealing
  with L1 regularized inversion as it makes the inverse problem more stable
  (no ringing in solution)
• Changed cost in pylops.optimization.solver.cg
  and pylops.optimization.solver.cgls to be L2 norms of residuals
• Fixed pylops.utils.dottest.dottest for imaginary vectors and to
  ensure u and v vectors are of same dtype of the operator

v1.13.0

• Added pylops.signalprocessing.Sliding1D and
  pylops.signalprocessing.Patch2D operators
• Added pylops.basicoperators.MemoizeOperator operator
• Added decay and analysis option in pylops.optimization.sparsity.ISTA and
  pylops.optimization.sparsity.FISTA solvers
• Added toreal and toimag methods to pylops.LinearOperator
• Make nr and nc optional in pylops.utils.dottest.dottest
• Fixed complex check in pylops.basicoperators.MatrixMult
  when working with complex-valued cupy arrays
• Fixed bug in data reshaping in check in
  pylops.avo.prestack.PrestackInversion
• Fixed loading error when using old cupy and/or cusignal

v1.12.0

• Modified all operators and solvers to work with cupy arrays
• Added eigs and solver submodules to optimization
• Added deps and backend submodules to utils
• Fixed bug in Convolve2D and ConvolveND when dealing with filters that have less dimensions than the input vector.

v1.11.1

• Fixed import of pyfttw when not available in pylops.signalprocessing.ChirpRadon3D

v1.11.0

• Added pylops.signalprocessing.ChirpRadon2D and
  pylops.signalprocessing.ChirpRadon3D operators.
• Fixed bug in the inferred dimensions for regularization data creation
  in pylops.optimization.leastsquares.NormalEquationsInversion,
  pylops.optimization.leastsquares.RegularizedInversion, and
  pylops.optimization.sparsity.SplitBregman.
• Changed dtype of pylops.HStack to allow automatic inference from
  dtypes of input operator.
• Modified dtype of pylops.waveeqprocessing.Marchenko operator to
  ensure that outputs of forward and adjoint are real arrays.
• Reverted to previous complex-friendly implementation of
  pylops.optimization.sparsity._softthreshold to avoid division by 0.

v1.10.0

• Added tosparse method to pylops.LinearOperator.
• Added kind=linear in pylops.signalprocessing.Seislet operator.
• Added kind to pylops.basicoperators.FirstDerivative.
  operator to perform forward and backward (as well as centered)
  derivatives.
• Added kind to pylops.optimization.sparsity.IRLS
  solver to choose between data or model sparsity.
• Added possibility to use scipy.sparse.linalg.lobpcg in
  pylops.LinearOperator.eigs and pylops.LinearOperator.cond.
• Added possibility to use scipy.signal.oaconvolve in
  pylops.signalprocessing.Convolve1D.
• Added NRegs to pylops.optimization.leastsquares.NormalEquationsInversion
  to allow providing regularization terms directly in the form of H^T H.

v1.9.1

• Changed internal behaviour of pylops.sparsity.OMP when
  niter_inner=0. Automatically reverts to Matching Pursuit algorithm.
• Changed handling of dtype in pylops.signalprocessing.FFT and
  pylops.signalprocessing.FFT2D to ensure that the type of the input
  vector is retained when applying forward and adjoint.
• Added dtype parameter to the FFT calls in the definition of the
  pylops.waveeqprocessing.MDD operation. This ensure that the type
  of the real part of G input is enforced to the output vectors of the
  forward and adjoint operations.

v1.9.0

• Added pylops.waveeqprocessing.Deghosting and
  pylops.signalprocessing.Seislet operators
• Added hard and half thresholds in pylops.optimization.sparsity.ISTA
  and pylops.optimization.sparsity.FISTA solvers
• Added prescaled input parameter to pylops.waveeqprocessing.MDC
  and pylops.waveeqprocessing.Marchenko
• Added sinc interpolation to pylops.signalprocessing.Interp
  (kind == 'sinc')
• Modified pylops.waveeqprocessing.marchenko.directwave to
  to model analytical responses from both sources of volume injection
  (derivative=False) and source of volume injection rate
  (derivative=True)
• Added pylops.LinearOperator.asoperator method to
  pylops.LinearOperator
• Added pylops.utils.signalprocessing.slope_estimate function
• Fix bug in pylops.signalprocessing.Radon2D and
  pylops.signalprocessing.Radon3D when onthefly=True returning the
  same result as when onthefly=False