R/f_val_calc_delta_proportion.R

In erikerhardt/isogasex: Isotopic gas exchange using TDL and Licor input. Updated version of package tdllicor

#' delta as proportion (Isotopic composition (d) as fraction)
#'
#' I prefer using the fraction for calculations and then converting to composition at the end
#'
#' First calculates R_obs with \code{\link{f_val_calc_isotope_ratio}}
#' \deqn{delta_proportion <- (R_obs / R_std) - 1}
#' this quantity is not in per mil
#'
#' @param obs_12C xxxPARAMxxx
#' @param obs_13C xxxPARAMxxx
#' @param R_std xxxPARAMxxx
#'
#' @return delta_proportion xxxRETURNxxx
#'
f_val_calc_delta_proportion <-
function# delta as proportion (Isotopic composition (d) as fraction)
###   I prefer using the fraction for calculations and then converting to composition at the end
(obs_12C
###
, obs_13C
###
, R_std
###
)
{
  ##details<<
  ## First calculates R_obs with \code{\link{f_val_calc_isotope_ratio}}
  ##\deqn{delta_proportion <- (R_obs / R_std) - 1}
  ## this quantity is not in per mil
  R_obs <- f_val_calc_isotope_ratio(obs_12C, obs_13C);
  delta_proportion <- (R_obs / R_std) - 1; # not in per mil

  return( delta_proportion );
  ### delta_proportion
}