prop2delta {isotracer}

Convert isotopic proportions to delta values

Description

This function performs the inverse of the operation performed by delta2prop().

Usage

prop2delta(x = NULL, Rstandard = NULL)

Arguments

x

Vector of proportions values.

Rstandard

String describing the isotopic measurement, e.g. "d15N", "d13C" and used to set automatically Rstandards (see the Section "Ratios for reference standards" for more details). Alternatively, a numeric value to use for Rstandard, e.g. 0.0036765.

Value

A vector of same length of x, containing the delta values based on the proportions of heavy isotope provided as x and the Rstandard provided.

Examples

prop15N <- c(0.00395, 0.02222, 0.00462, 0.00753, NA, 0.00422, 0.00492)

# Rstandard can be specified with a string for some preset references
d15N <- prop2delta(prop15N, "d15N")
d15N

# Rstandard can also be specified manually for non-preset references
d15N_manual <- prop2delta(prop15N, 0.0036765)
d15N_manual

# Call delta2prop() to get the detail of available references
delta2prop()