Create a LIBS Calibration Model — ls

Constructs a libs_calibration S3 object holding a fitted calibration model plus the underlying training data and figures of merit.

Usage

ls_calibration(
  element,
  wavelength_nm,
  concentrations,
  intensities,
  model,
  method = "univariate",
  lod = NULL,
  loq = NULL,
  r_squared = NULL,
  unit = "ppm"
)

Arguments

element: Character. Element symbol (e.g. "Ca", "Fe").
wavelength_nm: Numeric. Emission line wavelength used.
concentrations: Numeric vector. Known concentrations of standards.
intensities: Numeric vector. Measured peak intensities or areas (or ratios for internal_std). Same length as concentrations.
model: Fitted model object (e.g. lm, mvr).
method: Character. One of "univariate", "internal_std", "pls", "cf_libs". Default "univariate".
lod: Numeric. Limit of detection (3-sigma). Default NULL.
loq: Numeric. Limit of quantification (10-sigma). Default NULL.
r_squared: Numeric. Coefficient of determination. Default NULL.
unit: Character. Concentration unit, e.g. "ppm", "wt_pct", "mg_kg". Default "ppm".

Value

A libs_calibration S3 object.

Examples

conc <- c(100, 500, 1000, 2500, 5000)
ints <- conc * 0.12 + stats::rnorm(5, 0, 5)
m <- stats::lm(conc ~ ints)
cal <- ls_calibration("Ca", 393.37, conc, ints, model = m,
                      r_squared = summary(m)$r.squared)
print(cal)
#> <libs_calibration>
#> • Element: "Ca"
#> • Line: 393.37 nm
#> • Method: "univariate"
#> • Unit: "ppm"
#> • Standards: 5
#> • R-squared: 0.9995
#> • LOD: (not set)
#> • LOQ: (not set)