chemometrics.pseudo_voigt_spectra

chemometrics.pseudo_voigt_spectra(x, parameter)

Generates vector based on pseudo-Voigt profiles

The function takes a wavenumber vector (x) and a set of parameters with the shape 4xn. It generates a mechanistic approximation a spectrum based on pseudo Voigt peaks.

Parameters

• x ((n_wl, 1)) – evaluated wavelengths

• parameters ((4, n_peaks)) – parameter definition for voigt profiles. parameters[0, :] define the peak positions. parameters[1, :] is proportional to the peak area. parameters[2, :] define the percentage of Lorentzian to Gauss profile. parameters[3, :] define the half width at half height of the peak.

Returns

spectra – spectra with n_peaks evaluated voigt profiles

Return type

(n_wl, 1)

Notes

The pseudo-Voigt peaks are implemented similarly as described in [3]_. The parameters are chosen such that they do only affect one statistical property of the profile: The definition of the peak width is selected such that the Full Width at Half Maximum (FWHM) does not change when changing the relative contributions of the Gaussian/Lorentzian profile. Similarly, the peak height is not affected by the other parameters (peaks normalized by height not by area!). This approach to the peak height was chosen as the absolute peak height is a more intuitive parameter than the peak area.