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.

## Usage

```
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
)
```

## Arguments

- 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`

.

## Examples

```
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
)
#> # A tibble: 478 × 15
#> equation…¹ equat…² equat…³ indep…⁴ depen…⁵ long lat koppen dbh_m…⁶ dbh_m…⁷
#> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <chr> <dbl> <dbl>
#> 1 726f1d Larix … 10^(2.… DBH Total … -98.3 55.9 Dfc 0.2 2
#> 2 a4d879 Acer s… 10^(1.… DBH Total … NI NI Cfa 0.19 3.86
#> 3 b9ebe4 Alnus … exp(5.… DBH Whole … -123… 44.45 Csb 1.7 13.2
#> 4 5e2dea Viburn… 29.615… DBH Total … -66.… 45.97 Dfb 0.28 1.59
#> 5 21800b Pinus … exp(5.… DBH Total … NI NI Cfa; … 1 55
#> 6 1257b1 Abies exp(3.… DBH Total … NI NI Csb 8.7 111
#> 7 9e2124 Populu… 10^(1.… DBH Total … 127.5 45.33 Dwb 2.8 41.3
#> 8 74d0ce Ostrya… exp(4.… DBH Total … NRA NRA Dfb 1 9
#> 9 94f593 Liriod… 10^(0.… DBH Total … NI NI Cfa 0.42 8.53
#> 10 8c94e8 Nyssa … 10^(1.… DBH Total … NI NI Cfa 0.24 6.72
#> # … with 468 more rows, 5 more variables: sample_size <dbl>,
#> # dbh_units_original <chr>, dbh_unit_cf <dbl>, output_units_original <chr>,
#> # output_units_cf <dbl>, and abbreviated variable names ¹equation_id,
#> # ²equation_taxa, ³equation_allometry, ⁴independent_variable,
#> # ⁵dependent_variable, ⁶dbh_min_cm, ⁷dbh_max_cm
```