afc (version 1.4.0)

afc.me: 2AFC For Ordinal Polychotomous Observations And Ensemble Forecasts

Description

Routine to calculate the Generalized Discrimination Score (aka Two-Alternatives Forced Choice Score 2AFC) for the situation of polychotomous observations (ordinal) and ensemble forecasts

Usage

afc.me(obsv, fcst, m = 3)

Arguments

obsv

vector with polychotomous observations (values in 1,..,m)

fcst

two-dimensional array with ensemble forecasts; dim(fcst)[1] = length(obsv); dim(fcst)[2] = ensemble size

m

number of observation categories (default = 3)

Value

p.afc

Value of Generalized Discrimination (2AFC) Score

Details

This routine first ranks the ensemble forecasts (see rank.ensembles) and then calculates the 2AFC-score with Eq.18 of Mason and Weigel (2009).

References

S.J. Mason and A.P. Weigel, 2009. A generic verification framework for administrative purposes. Mon. Wea. Rev., 137, 331-349

See Also

afc rank.ensembles

Examples

  #Forecasts and observations of Nino-3.4 index
  #Load set of polychotomous observations (4 categories) and 9-member ensemble forecasts
  data(cnrm.nino34.me)
  obsv = cnrm.nino34.me$obsv
  fcst = cnrm.nino34.me$fcst

  #Calculate skill score
  afc.me(obsv,fcst,4)