set_relative_bounds: Set relative bounds on an NMRScaffold1D or NMRScaffold2D...

In ssokolen/rnmrfit: Robust NMR Lineshape Fitting in the Frequency Domain

Description

Although any NMRScaffold object can act as a boundary on another NMRScaffold object, this function provides a convenience method for generating such bounds using a simple set of lower and upper constraints on basic peak parameters such as position, height, width, etc... Note that the term "relative" refers to the fact that bounds are applied relative to the current values of the parameters.

Usage

set_relative_bounds(object, position = NULL, height = NULL,
  width = NULL, baseline = NULL, phase = NULL, normalized = FALSE,
  widen = FALSE, ...)

## S4 method for signature 'NMRScaffold1D'
set_relative_bounds(object, position = NULL,
  height = NULL, width = NULL, baseline = NULL, phase = NULL,
  normalized = TRUE, widen = FALSE)

Arguments

object	An NMRScaffold1D or NMRscaffold2D object. NMR data must be attached to object to enable normalization.
position	A vector of two elements corresponding to a lower and upper bound for peak position, where the value is taken as a fraction of the current position. Note that whether or not the normalized argument is set to TRUE has a big impact. If normalized is FALSE, the fraction is applied to the peak position in ppm (where even a small fraction has a very big impact). If normalized is TRUE, the fraction is effectively applied to a subset of the overall ppm range.
height	A vector of two elements corresponding to a lower and upper bound for peak height, where the value is taken as a fraction of the current height.
width	A vector of two elements corresponding to a lower and upper bound for peak width, where the value is taken as a fraction of the current width.
baseline	A vector of two elements corresponding to a lower and upper bound for baseline height, where the value is taken as a fraction of the current baseline height.
phase	A vector of two elements corresponding to a lower and upper bound for phase in radians, where the value is taken as a fraction of the current phase.
normalized	TRUE to set bounds in terms of the underlying data, where the x and y values of the data are scaled between 0 and 1. FALSE to use natural units of ppm/Hz and spectral intensity.
widen	FALSE to prevent new bounds from widening existing bounds.
...	Additional arguments passed to inheriting methods.

Details

In practice, relative bounds are primarily useful for preventing peak positions from drifting and for fine-tuning a fit once an initial optimization is performed. It is not recommended to use strict relative bounds based on rough initial parameter guesses.

Value

A new NMRScaffold1D or NMRScaffold2D object with modified parameters.

ssokolen/rnmrfit documentation built on May 23, 2019, 1:48 p.m.