sinreg: Function that carries out a sinusoidal regression

In ShellChron: Builds Chronologies from Oxygen Isotope Profiles in Shells

Description

Fits a sinusoid through data provided as an x and y vector and returns a list containing both the fitted curve and the parameters of that curve. Used to produce initial values for modeling data windows and later to find peaks in modeled julian day values to align the result to a cumulative age timeline.

Usage

sinreg(x, y, fixed_period = NA, plot = FALSE)

Arguments

x	Vector of x values of input data
y	Vector of y values of input data
fixed_period	Optional variable for fixing the period of the sinusoid in the depth domain. Defaults to NA, period is not fixed. Supply a single value to fix the period.
plot	Should the fitting result be plotted? TRUE/FALSE

Value

A list containing a vector of parameters of the fitted sinusoid and the fitted values belonging to each x value. Fitting parameters: I = the mean annual value of the sinusoid (height) A = the amplitude of the sinusoid Dper = the period of the sinusoid in x domain peak = the location of the peak in the sinusoid R2adj = the adjusted R^2 value of the fit p = the p-value of the fit

Examples

# Create dummy data
x <- seq(1000, 11000, 1000)
y <- sin((2 * pi * (seq(1, 11, 1) - 8 + 7 / 4)) / 7)
sinlist <- sinreg(x, y, plot = FALSE) # Run the function

Example output

ShellChron documentation built on July 5, 2021, 5:06 p.m.