dtmm.fft

Custom 2D FFT functions.

numpy, scipy and mkl_fft do not have fft implemented such that output argument can be provided. This implementation adds the output argument for fft2 and ifft2 functions.

Also, for mkl_fft and scipy, the computation can be performed in parallel using ThreadPool.

Module Contents

dtmm.fft.fft2(a, out=None)

Computes fft2 of the input complex array.

Parameters

• a (array_like) – Input array (must be complex).

• out (array or None, optional) – Output array. Can be same as input for fast inplace transform.

Returns

out – Result of the transformation along the last two axes.

Return type

complex ndarray

dtmm.fft.ifft2(a, out=None)

Computes ifft2 of the input complex array.

Parameters

• a (array_like) – Input array (must be complex).

• out (array or None, optional) – Output array. Can be same as input for fast inplace transform.

Returns

out – Result of the transformation along the last two axes.

Return type

complex ndarray

dtmm.fft.mfft2(a, overwrite_x=False)

Computes matrix fft2 on a matrix of shape (…, n,n,4,4).

This is identical to np.fft2(a, axes = (-4,-3))

Parameters

• a (array_like) – Input array (must be complex).

• overwrite_x (bool) – Specifies whether original array can be destroyed (for inplace transform)

Returns

out – Result of the transformation along the (-4,-3) axes.

Return type

complex ndarray

dtmm.fft.mifft2(a, overwrite_x=False)

Computes matrix ifft2 on a matrix of shape (…, n,n,4,4).

This is identical to np.ifft2(a, axes = (-4,-3))

Parameters

• a (array_like) – Input array (must be complex).

• overwrite_x (bool) – Specifies whether original array can be destroyed (for inplace transform)

Returns

out – Result of the transformation along the (-4,-3) axes.

Return type

complex ndarray

dtmm.fft.mfft(a, overwrite_x=False)

Computes matrix fft on a matrix of shape (…, n,4,4).

This is identical to np.fft2(a, axis = -3)

Parameters

• a (array_like) – Input array (must be complex).

• overwrite_x (bool) – Specifies whether original array can be destroyed (for inplace transform)

Returns

out – Result of the transformation along the (-4,-3) axes.

Return type

complex ndarray

dtmm.fft.fft(a, overwrite_x=False)

Computes fft on a matrix of shape (…, n).

This is identical to np.fft2(a)

Parameters

• a (array_like) – Input array (must be complex).

• overwrite_x (bool) – Specifies whether original array can be destroyed (for inplace transform)

Returns

out – Result of the transformation along the (-4,-3) axes.

Return type

complex ndarray

dtmm.fft.ifft(a, overwrite_x=False)

Computes ifft on a matrix of shape (…, n).

This is identical to np.ifft2(a)

Parameters

• a (array_like) – Input array (must be complex).

• overwrite_x (bool) – Specifies whether original array can be destroyed (for inplace transform)

Returns

out – Result of the transformation along the (-4,-3) axes.

Return type

complex ndarray