Source code for pylops.basicoperators.Imag

import numpy as np

from pylops import LinearOperator
from pylops.utils.backend import get_array_module

[docs]class Imag(LinearOperator): r"""Imag operator. Return the imaginary component of the input as a real value. The adjoint returns a complex number with zero real component and the imaginary component set to the real component of the input. Parameters ---------- dims : :obj:`int` or :obj:`tuple` Number of samples for each dimension dtype : :obj:`str`, optional Type of elements in input array. Attributes ---------- shape : :obj:`tuple` Operator shape explicit : :obj:`bool` Operator contains a matrix that can be solved explicitly (``True``) or not (``False``) Notes ----- In forward mode: .. math:: y_{i} = \Im\{x_{i}\} \quad \forall i=0,\ldots,N-1 In adjoint mode: .. math:: x_{i} = 0 + i\Re\{y_{i}\} \quad \forall i=0,\ldots,N-1 """ def __init__(self, dims, dtype="complex128"): self.shape = (, self.dtype = np.dtype(dtype) self.rdtype = np.real(np.ones(1, self.dtype)).dtype self.explicit = False self.clinear = False def _matvec(self, x): ncp = get_array_module(x) return ncp.imag(x).astype(self.rdtype) def _rmatvec(self, x): ncp = get_array_module(x) return (0 + 1j * ncp.real(x)).astype(self.dtype)