MSE {SeaVal}

Mean Square Error of ensemble forecasts.

Description

Derives the MSE of ensemble forecasts stored in long data tables. Can also handle point forecast.

Usage

MSE(
  dt,
  f,
  o = "obs",
  by = by_cols_ens_fc_score(),
  pool = "year",
  mem = "member",
  dim.check = TRUE
)

Arguments

dt

Data table containing the predictions.

f

column name of the prediction.

o

column name of the observations.

by

column names of grouping variables, all of which need to be columns in dt. Default is to group by all instances of month, season, lon, lat, system and lead_time that are columns in dt.

pool

column name(s) for the variable(s) along which is averaged, typically just 'year'.

mem

Name of the column identifying the ensemble member. Only used if check_dimension is TRUE. Is NULL for a point forecast.

dim.check

Logical. If True, a simple test whether the dimensions match up is conducted: The data table should only have one row for each level of c(by,pool,mem)

Value

A data table with the scores

Examples

dt = data.table(fc = 1:4,obs = c(4,4,7,7),member = c(1,2,1,2),year = c(1999,1999,2000,2000))
MSE(dt,f = 'fc')