sads_svd

TRXASprefitpack.driver.sads_svd(escan_time: ndarray, fwhm: float, eigval: ndarray, V: ndarray, c: ndarray, exclude: Optional[str] = None, irf: Optional[str] = 'g', eta: Optional[float] = None, intensity: Optional[ndarray] = None, cond_num: Optional[float] = 0) → Tuple[ndarray, ndarray][source]

Calculate species associated difference spectrum from experimental energy scan data (using svd)

Parameters

  • escan_time – time delay for each energy scan data

  • fwhm – full width at half maximum of instrumental response function

  • eigval – eigenvalue of rate equation matrix

  • V – eigenvector of rate equation matrix

  • c – coefficient to match initial condition of rate equation

  • exclude –

    exclude either ‘first’ or ‘last’ element or both ‘first’ and ‘last’ element.

    • ’first’ : exclude first element

    • ’last’ : exclude last element

    • ’first_and_last’ : exclude both first and last element

    • None : Do not exclude any element [default]

  • irf –

    shape of instrumental response function [default: g]

    • ’g’: normalized gaussian distribution,

    • ’c’: normalized cauchy distribution,

    • ’pv’: pseudo voigt profile \((1-\eta)g(t, {fwhm}) + \eta c(t, {fwhm})\)

  • eta – mixing parameter for pseudo voigt profile (only needed for pseudo voigt profile)

  • intensity – intensity of energy scan dataset

  • cond_num – conditional number to turncate svd

Returns

Tuple of calculated species associated difference spectrum of each component, and retrieved intensity of energy scan from sads and model excited state components

Note

  1. eigval, V, c should be obtained from solve_model

  2. To calculate species associated difference spectrum of n excited state species, you should measure at least n+1 energy scan

  3. Difference spectrum of ground state is zero, so ground state species should be excluded from rate equation or via exclude option.