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 either on 12CO2/13CO2 mole fractions (gainoffset method) or on the CO2 and d13C values (linreg).
fit_carbon_regression(
ref_data,
method,
calibration_half_width,
plot_regression_data = FALSE,
plot_dir = "/dev/null",
site,
min_nobs = NA
)Returns a data.frame of calibration parameters. If
method == "gainoffset", then data.frame includes
gain and offset parameters for 12CO2 and 13CO2, and r^2
values for each regression. If method == "linreg",
then data.frame includes slope, intercept, and r^2 values
for d13C and CO2 values.
Reference data.frame from which to estimate calibration parameters.
Are we using the gain-and-offset method ("gainoffset"), formerly called the Bowling et al. 2003 method in this package, or direct linear regression of d13C and CO2 mole fractions ("linreg")?
Determines the period (in days) from which reference data are selected (period is 2*calibration_half_width).
True or false - should we plot the data used in the regression? Useful for debugging.
If plot_regression_data is true, where should the plots be saved?
Needed for regression plots.
Minimum number of high-frequency observations to define a peak.
Rich Fiorella rfiorella@lanl.gov