Return a list of options for an ABfit analysis.
abfit_opts(
init_damping = 5,
maxiters = 1024,
max_shift = 10,
max_damping = 15,
max_phase = 360,
lambda = NULL,
ppm_left = 4,
ppm_right = 0.2,
zp = TRUE,
bl_ed_pppm = 2,
auto_bl_flex = TRUE,
bl_comps_pppm = 15,
export_sp_fit = FALSE,
max_asym = 0.25,
max_basis_shift = 1,
max_basis_damping = 2,
maxiters_pre = 1000,
algo_pre = "NLOPT_LN_NELDERMEAD",
min_bl_ed_pppm = NULL,
max_bl_ed_pppm = 7,
auto_bl_flex_n = 20,
pre_fit_bl_ed_pppm = 1,
remove_lip_mm_prefit = FALSE,
pre_align = TRUE,
max_pre_align_shift = 0.1,
pre_align_ref_freqs = c(2.01, 3.03, 3.22),
noise_region = c(-0.5, -2.5),
optimal_smooth_criterion = "maic",
aic_smoothing_factor = 5,
anal_jac = TRUE,
pre_fit_ppm_left = 4,
pre_fit_ppm_right = 1.8,
phi1_optim = FALSE,
phi1_init = 0,
max_dphi1 = 0.2,
max_basis_shift_broad = 1,
max_basis_damping_broad = 2,
ahat_calc_method = "lh_pnnls",
prefit_phase_search = TRUE,
freq_reg = NULL
)
init_damping | initial value of the Gaussian global damping parameter (Hz). Very poorly shimmed or high field data may benefit from a larger value. |
---|---|
maxiters | The maximum number of iterations to run for the detailed fit. |
max_shift | The maximum allowable shift to be applied in the optimisation phase of fitting (Hz). |
max_damping | maximum permitted value of the global damping parameter (Hz). |
max_phase | the maximum absolute permitted value of the global zero-order phase term (degrees). Note, the prefit_phase_search option is not constrained by this term. |
lambda | manually set the the baseline smoothness parameter. |
ppm_left | downfield frequency limit for the fitting range (ppm). |
ppm_right | upfield frequency limit for the fitting range (ppm). |
zp | zero pad the data to twice the original length before fitting. |
bl_ed_pppm | manually set the the baseline smoothness parameter (ED per ppm). |
auto_bl_flex | automatically determine the level of baseline smoothness. |
bl_comps_pppm | spline basis density (signals per ppm). |
export_sp_fit | add the fitted spline functions to the fit result. |
max_asym | maximum allowable value of the asymmetry parameter. |
max_basis_shift | maximum allowable frequency shift for individual basis signals (Hz). |
max_basis_damping | maximum allowable Lorentzian damping factor for individual basis signals (Hz). |
maxiters_pre | maximum iterations for the coarse (pre-)fit. |
algo_pre | optimisation method for the coarse (pre-)fit. |
min_bl_ed_pppm | minimum value for the candidate baseline flexibility analyses (ED per ppm). |
max_bl_ed_pppm | minimum value for the candidate baseline flexibility analyses (ED per ppm). |
auto_bl_flex_n | number of candidate baseline analyses to perform. |
pre_fit_bl_ed_pppm | level of baseline flexibility to use in the coarse fitting stage of the algorithm (ED per ppm). |
remove_lip_mm_prefit | remove broad signals in the coarse fitting stage of the algorithm. |
pre_align | perform a pre-alignment step before coarse fitting. |
max_pre_align_shift | maximum allowable shift in the pre-alignment step (ppm). |
pre_align_ref_freqs | a vector of prominent spectral frequencies used in the pre-alignment step (ppm). |
noise_region | spectral region to estimate the noise level (ppm). |
optimal_smooth_criterion | method to determine the optimal smoothness. |
aic_smoothing_factor | modification factor for the AIC calculation. |
anal_jac | use a analytical approximation to the jacobian in the detailed fitting stage. |
pre_fit_ppm_left | downfield frequency limit for the fitting range in the coarse fitting stage of the algorithm (ppm). |
pre_fit_ppm_right | upfield frequency limit for the fitting range in the coarse fitting stage of the algorithm (ppm). |
phi1_optim | apply and optimise a frequency dependant phase term. |
phi1_init | initial value for the frequency dependant phase term (ms). |
max_dphi1 | maximum allowable change from the initial frequency dependant phase term (ms). |
max_basis_shift_broad | maximum allowable shift for broad signals in the basis (Hz). Determined based on their name beginning with Lip or MM. |
max_basis_damping_broad | maximum allowable Lorentzian damping for broad signals in the basis (Hz). Determined based on their name beginning with Lip or MM. |
ahat_calc_method | method to calculate the metabolite amplitudes. May be one of: "lh_pnnls" or "ls". |
prefit_phase_search | perform a 1D search for the optimal phase in the prefit stage of the algorithm. |
freq_reg | frequency shift parameter. |
full list of options.
opts <- abfit_opts(ppm_left = 4.2, noise_region = c(-1, -3))