sigdrift_onset: Drift onset time of the sigmoidal-drift model

In mnirs: Muscle Near-Infrared Spectroscopy Processing and Analysis

Drift onset time of the sigmoidal-drift model

Description

The time at which a sigmoid of the given shape reaches the drift_fraction fraction of its amplitude, by the analytic inverse of each shape (see sigmoidal_drift()). Vectorised over the numeric parameters; shape is a single string.

Usage

sigdrift_onset(A, B, xmid, slope, drift_fraction, shape)

Arguments

A	A numeric parameter for the starting asymptote of the response variable.
B	A numeric parameter for the ending asymptote of the response variable.
xmid	A numeric parameter for the time at the inflection point (the steepest point) of the curve, in units of the predictor variable t.
slope	A numeric parameter for the response rate dx/dt at the inflection xmid.
drift_fraction	A numeric fraction of the primary amplitude B - A in ⁠(0.5, 1)⁠ at which the linear drift begins, where the sigmoid reaches A + drift_fraction * (B - A).
shape	Character; the 4-parameter sigmoidal shape. One of "symmetric" (default; logistic()), "gompertz" (gompertz()), or "gompertz_left" (gompertz_left()).

Value

A numeric vector of onset times.

mnirs documentation built on Sept. 13, 2026, 1:06 a.m.