new_equations: Modify the original equation table
In forestgeo/allodb: Tree Biomass Estimation at Extra-Tropical Forest Plots

Description Usage Arguments Value Examples

This function modifies the original equation table to be used in other functions of the package including: subset the original equation table, add new equations, and choose whether to include equations with a height allometry.

new_equations(
  subset_taxa = "all",
  subset_climate = "all",
  subset_region = "all",
  subset_ids = "all",
  subset_output = c("Total aboveground biomass", "Whole tree (above stump)"),
  new_taxa = NULL,
  new_allometry = NULL,
  new_coords = NULL,
  new_min_dbh = NULL,
  new_max_dbh = NULL,
  new_sample_size = NULL,
  new_unit_dbh = "cm",
  new_unit_output = "kg",
  new_input_var = "DBH",
  new_output_var = "Total aboveground biomass",
  use_height_allom = TRUE
)

`subset_taxa`	character vector with taxa to be kept. Default is "all", in which case all taxa are kept.
`subset_climate`	character vector with Koppen climate classification to be kept. Default is "all", in which case all climates are kept.
`subset_region`	character vector with name of location(s) or country(ies) or broader region(s) (eg. "Europe", "North America") to be kept. Default is "all", in which case all regions/countries are kept.
`subset_ids`	character vector with equation IDs to be kept. Default is "all", in which case all equations are kept.
`subset_output`	What dependent variable(s) should be provided in the output? Default is "Total aboveground biomass" and "Whole tree (above stump)", other possible values are: "Bark biomass", "Branches (dead)", "Branches (live)", "Branches total (live, dead)", "Foliage total", "Height", "Leaves", "Stem (wood only)", "Stem biomass", "Stem biomass (with bark)", "Stem biomass (without bark)", "Whole tree (above and belowground)". Be aware that currently only a few equations represent those other variables, so estimated values might not be very accurate.
`new_taxa`	character string or vector specifying the taxon (or taxa) for which the allometry has been calibrated.
`new_allometry`	a character string with the allometric equation.
`new_coords`	a vector or matrix of coordinates (longitude, latitude) of the calibration data.
`new_min_dbh`	numerical value, minimum DBH for which the equation is valid (in cm). Default is `NULL` (nothing is added).
`new_max_dbh`	numerical value, maximum DBH for which the equation is valid (in cm). Default is `NULL` (nothing is added).
`new_sample_size`	number of measurements with which the allometry was calibrated. Default is `NULL` (nothing is added).
`new_unit_dbh`	character string with unit of DBH in the equation (either `cm`, `mm` or `inch`). Default is "cm".
`new_unit_output`	character string with unit of equation output (either "g", "kg", "Mg" or "lbs" if the output is a mass, or "m" if the output is a height).
`new_input_var`	independent variable(s) needed in the allometry. Default is "DBH", other option is "DBH, H".
`new_output_var`	dependent variable estimated by the allometry. Default is "Total aboveground biomass".
`use_height_allom`	a logical value. In allodb we use Bohn et al. (2014) for European sites. User need to provide height allometry when needed to calculate AGB. Default is `TRUE`.

An object of class "data.frame" of new equations.

new_equations(
  new_taxa = "Faga",
  new_allometry = "exp(-2+log(dbh)*2.5)",
  new_coords = c(-0.07, 46.11),
  new_min_dbh = 5,
  new_max_dbh = 50,
  new_sample_size = 50
)