Fitting

EVA.core.fitting.fit_data.fit_gaussian_lmfit(x_data, y_data, peak_params, bg_params)

Fit a model containing N Gaussians using the least-squared method.

Parameters:

  • x_data (ndarray) – x-values to fit for

  • y_data (ndarray) – y-values to fit for

  • peak_params (dict) – dictionary containing each peak to fit for and fit settings for each peak

  • bg_params (dict) – dictionary containing the background parameters and settings.

Return type:

ModelResult

Returns:

lmfit model result object.

EVA.core.fitting.fit_data.fit_model_lmfit(x_data, y_data, peak_params, bg_params, model_params, constrain_scale=None)

Fit a sum of previously defined fixed-shape N-Gaussian spectra with scale factors and shift parameters for each spectrum using the least-squares method.

For example, if a spectrum containing multiple Gaussians has previously been fitted, this function can be used to fit the shape of that spectrum to another dataset, holding the mean and standard deviations of the previously fitted model fixed, only varying the scale factor and offset of the model.

Parameters:

  • x_data (ndarray) – x-values to fit for

  • y_data (ndarray) – y-values to fit for

  • peak_params (dict) – parameter dictionary for the gaussian peaks within each model

  • bg_params (dict) – background parameters

  • model_params (dict) – parameter dictionary for each model containing scale and offset parameters

  • constrain_scale (float | None) – if not None, all scale parameters will obey the constraint A + B … + Z = constrain_scale

Return type:

ModelResult

Returns:

lmfit model result object.

EVA.core.fitting.fit_data.scaled_shifted_gaussians(x, scale, x0, params)

Spectrum of multiple Gaussians, one for each set of peak parameters in ‘params’, with a vertical shift parameter x0 and an overall scale factor ‘scale’

Parameters:

  • x (ndarray) – input array to calculate for

  • scale (float) – intensity scale factor

  • x0 (float) – vertical offset parameter

  • params (dict) – Gaussian peak parameter dict

Return type:

ndarray

Returns:

Array containing total spectrum from sum of all Gaussians.