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spectrochempy.general_hamming¶

general_hamming(alpha=None)def general_hamming(dataset, alpha, **kwargs)[source]¶

Calculate generalized Hamming apodization.

For multidimensional NDDataset, the apodization is by default performed on the last dimension.

The data in the last dimension MUST be time-domain or dimensionless, otherwise an error is raised.

Functional form of apodization window :

\[w(n) = \alpha - \left(1 - \alpha\right) \cos\left(\frac{2\pi{n}}{M-1}\right) \qquad 0 \leq n \leq M-1\]

where M is the number of point of the input dataset.

Both the common Hamming window and Hann window are special cases of the generalized Hamming window with \(\alpha\) = 0.54 and :math:alpha = 0.5, respectively

Parameters

dataset (array.) – Input dataset.
alpha (float) – The window coefficient, :math:alpha.
**kwargs – Optional keyword parameters (see Other Parameters).

Returns

apodized – Dataset.
apod_arr – The apodization array only if ‘retapod’ is True.

Other Parameters

dim (str or int, keyword parameter, optional, default=’x’) – Specify on which dimension to apply the apodization method. If dim is specified as an integer it is equivalent to the usual axis numpy parameter.
inv (bool, keyword parameter, optional, default=False) – True for inverse apodization.
rev (bool, keyword parameter, optional, default=False) – True to reverse the apodization before applying it to the data.
inplace (bool, keyword parameter, optional, default=False) – True if we make the transform inplace. If False, the function return a new dataset.
retapod (bool, keyword parameter, optional, default=False) – True to return the apodization array along with the apodized object.