verify {verification}R Documentation

Verification function

Description

Based on the type of inputs, this function calculates a range of verification statistics and skill scores. Additionally, it creates a verify class object that can be further analyzed.

Usage

    verify(obs, pred,  tseries= NULL, baseline = NULL, 
           frcst.type = "prob", obs.type = "binary",  thresholds = seq(0,1,0.1) )
       

Arguments

obs The value with which the verifications are verified.
pred Prediction of event. The prediction may be in the form of the a point prediction or the probability of a forecast.
tseries Optional time series vector. This allows certain types of plots to be made.
baseline In meteorology, climatology is the baseline that represents the no-skill forecast. In other fields this field would differ. This field is used to calculate certain skill scores. If left NULL, these statistics are calculated using sample climatology.
frcst.type Forecast type. Either "prob", "binary", or "cont". Defaults to "prob"
obs.type Observation type. Either "binary", or "cont". Defaults to "binary"
thresholds Thresholds to be considered for point forecasts of continuous events.

Value

An object of the verify class. Depending on the type of data used, the following information may be returned. The following notation is used to describe which values are produced for which type of forecast/observations. (BB = binary/binary, PB = probablistic/binary, CC = continuous/continuous.)

BS Brier Score (PB)
BSS Brier Skill Score(PB)
SS Skill Score (BB)
hit.rate Hit rate, aka PODy, $h$ (PB)
false.alarm.rate False alarm rate, PODn, $f$ (PB)
TS Threat Score or Critical Success Index (CSI)(BB)
ETS Equitable Threat Score (BB)
BIAS Bias (BB)
PC Percent correct or hit rate (BB)
Cont.Table Contingency Table (BB)
HSS Heidke Skill Score(BB)
KSS Kuniper Skill Score (BB)
ME Mean error (CC)
MSE Mean-squared error (CC)
MAE Mean absolute error (CC)

Author(s)

Matt Pocernich <pocernic@rap.ucar.edu>

References

Wilks, D. S. (1995) Statistical Methods in the Atmospheric Sciences Chapter 7, San Diego: Academic Press.

WMO Joint WWRP/WGNE Working Group on Verification Website

http://www.bom.gov.au/bmrc/wefor/staff/eee/verif/verif_web_page.html

World Meteorological Organization Verification Website

http://www.wmo.ch/web/aom/pwsp/Verification.html

Examples

# binary/binary example
obs<- round(runif(100))
pred<- round(runif(100))

A<- verify(obs, pred, frcst.type = "binary", obs.type = "binary")
summary(A)
#  probabilistic/ binary example
pred<- runif(100)
A<- verify(obs, pred, frcst.type = "prob", obs.type = "binary")
summary(A)
# continuous/ continuous example
obs<- rnorm(100)
pred<- rnorm(100)
baseline <- rnorm(100, sd = 0.5) 

A<- verify(obs, pred, baseline = baseline,  frcst.type = "cont", obs.type = "cont")
summary(A)

[Package verification version 1.02 Index]