jax.scipy.fft.dct#

jax.scipy.fft.dct(x, type=2, n=None, axis=- 1, norm=None)[source]#

Return the Discrete Cosine Transform of arbitrary type sequence x.

LAX-backend implementation of scipy.fft._realtransforms.dct().

Original docstring below.

Parameters
  • x (array_like) – The input array.

  • type ({1, 2, 3, 4}, optional) – Type of the DCT (see Notes). Default type is 2.

  • n (int, optional) – Length of the transform. If n < x.shape[axis], x is truncated. If n > x.shape[axis], x is zero-padded. The default results in n = x.shape[axis].

  • axis (int, optional) – Axis along which the dct is computed; the default is over the last axis (i.e., axis=-1).

  • norm ({"backward", "ortho", "forward"}, optional) – Normalization mode (see Notes). Default is “backward”.

Returns

y – The transformed input array.

Return type

ndarray of real

References

1

‘A Fast Cosine Transform in One and Two Dimensions’, by J. Makhoul, IEEE Transactions on acoustics, speech and signal processing vol. 28(1), pp. 27-34, DOI:10.1109/TASSP.1980.1163351 (1980).

2

Wikipedia, “Discrete cosine transform”, https://en.wikipedia.org/wiki/Discrete_cosine_transform