nnmnkwii.util.delta¶

nnmnkwii.util.delta(x, window)[source]¶

Returns delta features given a static features and a window.

Parameters:	x (numpy.ndarray) – Input static features, of shape (`T x D`). window (numpy.ndarray) – Window coefficients.
Returns:	Delta features, shape　(`T x D`).
Return type:	(ndarray)

Examples

>>> from nnmnkwii.util import delta
>>> T, static_dim = 10, 24
>>> x = np.random.rand(T, static_dim)
>>> window = np.array([-0.5, 0.0, 0.5]) # window for delta feature
>>> y = delta(x, window)
>>> assert x.shape == y.shape