Imag

This example shows how to use the pylops.basicoperators.Imag operator. This operator returns the imaginary part of the data as a real value in forward mode, and the real part of the model as an imaginary value in adjoint mode (with zero real part).

import matplotlib.pyplot as plt
import numpy as np

import pylops

plt.close("all")

Let’s define a Imag operator \(\mathbf{\Im}\) to extract the imaginary component of the input.

M = 5
x = np.arange(M) + 1j * np.arange(M)[::-1]
Rop = pylops.basicoperators.Imag(M, dtype="complex128")

y = Rop * x
xadj = Rop.H * y

_, axs = plt.subplots(1, 3, figsize=(10, 4))
axs[0].plot(np.real(x), lw=2, label="Real")
axs[0].plot(np.imag(x), lw=2, label="Imag")
axs[0].legend()
axs[0].set_title("Input")
axs[1].plot(np.real(y), lw=2, label="Real")
axs[1].plot(np.imag(y), lw=2, label="Imag")
axs[1].legend()
axs[1].set_title("Forward of Input")
axs[2].plot(np.real(xadj), lw=2, label="Real")
axs[2].plot(np.imag(xadj), lw=2, label="Imag")
axs[2].legend()
axs[2].set_title("Adjoint of Forward")
plt.tight_layout()