pylops.Sum¶
-
class
pylops.
Sum
(dims, dir, dtype='float64')[source]¶ Sum operator.
Sum along an axis of a multi-dimensional array (at least 2 dimensions are required) in forward model, and spread along the same axis in adjoint mode.
Parameters: Notes
Given a two dimensional array, the Sum operator re-arranges the input model into a multi-dimensional array of size
dims
and sums values along directiondir
:\[y_j = \sum_i x_{i, j}\]In adjoint mode, the data is spread along the same direction:
\[x_{i, j} = y_j \quad \forall i=0, N-1\]Attributes: Methods
__init__
(dims, dir[, dtype])Initialize this LinearOperator. adjoint
()Hermitian adjoint. apply_columns
(cols)Apply subset of columns of operator cond
([uselobpcg])Condition number of linear operator. conj
()Complex conjugate operator div
(y[, niter])Solve the linear problem \(\mathbf{y}=\mathbf{A}\mathbf{x}\). dot
(x)Matrix-matrix or matrix-vector multiplication. eigs
([neigs, symmetric, niter, uselobpcg])Most significant eigenvalues of linear operator. matmat
(X)Matrix-matrix multiplication. matvec
(x)Matrix-vector multiplication. rmatmat
(X)Adjoint matrix-matrix multiplication. rmatvec
(x)Adjoint matrix-vector multiplication. todense
()Return dense matrix. tosparse
()Return sparse matrix. transpose
()Transpose this linear operator.