jax.numpy.fft.ifft2

Contents

jax.numpy.fft.ifft2#

jax.numpy.fft.ifft2(a, s=None, axes=(-2, -1), norm=None)[source]#

Compute a two-dimensional inverse discrete Fourier transform.

JAX implementation of numpy.fft.ifft2().

Parameters:

  • a (ArrayLike) – input array. Must have a.ndim >= 2.

  • s (Shape | None | None) – optional length-2 sequence of integers. Specifies the size of the output in each specified axis. If not specified, it will default to the size of a along the specified axes.

  • axes (Sequence[int]) – optional length-2 sequence of integers, default=(-2,-1). Specifies the axes along which the transform is computed.

  • norm (str | None | None) – string, default=”backward”. The normalization mode. “backward”, “ortho” and “forward” are supported.

Returns:

An array containing the two-dimensional inverse discrete Fourier transform of a along given axes.

Return type:

Array

See also

Examples

jnp.fft.ifft2 computes the transform along the last two axes by default.

>>> x = jnp.array([[[1, 3],
...                 [2, 4]],
...                [[5, 7],
...                 [6, 8]]])
>>> with jnp.printoptions(precision=2, suppress=True):
...   jnp.fft.ifft2(x)
Array([[[ 2.5+0.j, -1. +0.j],
        [-0.5+0.j,  0. +0.j]],

       [[ 6.5+0.j, -1. +0.j],
        [-0.5+0.j,  0. +0.j]]], dtype=complex64)

When s=[2, 3], dimension of the transform along axes (-2, -1) will be (2, 3) and dimension along other axes will be the same as that of input.

>>> with jnp.printoptions(precision=2, suppress=True):
...   jnp.fft.ifft2(x, s=[2, 3])
Array([[[ 1.67+0.j  , -0.08+1.01j, -0.08-1.01j],
        [-0.33+0.j  , -0.08-0.14j, -0.08+0.14j]],

       [[ 4.33+0.j  ,  0.58+2.17j,  0.58-2.17j],
        [-0.33+0.j  , -0.08-0.14j, -0.08+0.14j]]], dtype=complex64)

When s=[2, 3] and axes=(0, 1), shape of the transform along axes (0, 1) will be (2, 3) and dimension along other axes will be same as that of input.

>>> with jnp.printoptions(precision=2, suppress=True):
...   jnp.fft.ifft2(x, s=[2, 3], axes=(0, 1))
Array([[[ 2.33+0.j  ,  3.67+0.j  ],
        [ 0.33+1.15j,  0.67+1.73j],
        [ 0.33-1.15j,  0.67-1.73j]],

       [[-1.33+0.j  , -1.33+0.j  ],
        [-0.33-0.58j, -0.33-0.58j],
        [-0.33+0.58j, -0.33+0.58j]]], dtype=complex64)
Contents