sads_svd

TRXASprefitpack.driver.sads_svd(escan_time: ndarray, fwhm: float, eigval: ndarray, V: ndarray, c: ndarray, exclude: Tuple[int] | None = None, irf: str | None = 'g', eta: float | None = None, intensity: ndarray | None = None, cond_num: float | None = 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 –

    list of indices of species to exclude in SADS calculation

    • [0] : exclude first element

    • [-1] : exclude last element

    • [i1, i2, …, in] : exclude i1, i2, …, in

    • 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.