fit_water_regression: Estimate slope/intercept of water isotope calibration...

In SPATIAL-Lab/NEONiso: Tools to Calibrate and Work with NEON Atmospheric Isotope Data

Estimate slope/intercept of water isotope calibration regression

Description

Performs regression between measured and known carbon isotope and mole fractions to generate a transfer function and associated uncertainty estimates using both 5-fold and leave-one-out cross-validation methods. Regression occurs on d18O and d2H values.

Usage

fit_water_regression(
  ref_data,
  calibration_half_width,
  slope_tolerance,
  r2_thres,
  plot_regression_data = FALSE,
  plot_dir = "/dev/null",
  site,
  min_nobs = NA
)

Arguments

ref_data	Reference data.frame from which to estimate calibration parameters.
calibration_half_width	Determines the period (in days) from which reference data are selected (period is 2*calibration_half_width).
slope_tolerance	Allows for filtering of slopes that deviate from 1 by slope_tolerance.
r2_thres	What is the minimum r2 value permitted in a 'useful' calibration relationship.
plot_regression_data	True or false - should we plot the data used in the regression? Useful for debugging.
plot_dir	If plot_regression_data is true, where should the plots be saved?
site	Needed for regression plots.
min_nobs	Minimum number of high-frequency observations to define a peak.

Value

Returns a data.frame of calibration parameters. Output data.frame includes slope, intercept, and r^2 values for d13C and CO2 values.

SPATIAL-Lab/NEONiso documentation built on Feb. 27, 2025, 7:19 a.m.