RMSE cost function for BiomeE

Cost function for parameter calibration, which computes the root mean squared error (RMSE) between BiomeE simulations (using the input set of parameters) and observed target variables. Cost function for parameter calibration, which computes the RMSE for the biomee model fitting target variables 'GPP','LAI','Density' and 'Biomass' for a given set of parameters.

cost_rmse_biomee(par, obs, drivers)

Arguments

par

A vector containing parameter values for 'phiRL', 'LAI_light', 'tf_base', 'par_mort' in that order.

obs

A nested data frame of observations, following the structure of biomee_validation, for example.

drivers

A nested data frame of driver data, for example biomee_gs_leuning_drivers.

Value

The root mean squared error (RMSE) between the observed and simulated values of 'GPP','LAI','Density' and 'Biomass' (all variables have the same weight). Relative errors (difference divided by observed values) are used instead of absolute errors. The cost function performs a BiomeE model run for parameter values par and model drivers drivers given as arguments, producing the simulated values used to compute the RMSE.

Examples

# \donttest{
# Compute RMSE for a set of
# model parameter values
# and example data
cost_rmse_biomee(
 par = c(3.5, 3.5, 1, 1),
 obs = biomee_validation,
 drivers = biomee_gs_leuning_drivers
)
#> [1] 0.2985452
# }