tverify {ternvis}

Verification of ternary forecasts / observations

Description

Function to create verification information associated with a set of forecasts p and associated observations o.

Usage

tverify(p, o, q, forceq, ncirc, L)

## Default S3 method:
tverify(p = cbind(1, 1, 1)/3, o = cbind(0, 0, 1), 
        q = cbind(1, 1, 1)/3, forceq = FALSE, 
        ncirc = 11, L = diag(c(1, 1, 1))/sqrt(2))
## S3 method for class 'tverify'
plot(x, thresh = 0, lsharp = TRUE, 
     L = diag(c(1, 1, 1))/sqrt(2),...)

Arguments

p

An n-by-3 matrix of ternary forecasts.

o

An n-by-3 matrix of ternary observations.

q

A 1-by-3 matrix containing the climatology.

forceq

A logical. If forceq = TRUE then the input climatology q is used. If forceq = FALSE a climatology is calculated from o.

ncirc

Controls discretisation of barycentric coordinates. (The number of hexagons along each side of the triangle.)

x

An object of the tverify class (as produced by tverify or tgetcal.

thresh

A ‘threshold’ number of forecasts in a ‘bin’, below which the forecast will not be plotted. (Prevents diagram being cluttered by very rare forecasts).

lsharp

Logical controlling whether a ternary sharpness diagram is to be included.

L

A quadratic scoring matrix. The matrix for the Brier score is the default. Full functionality for other scores not yet implemented.

...

Not used.

Value

An object of class tverify, which is a list containing the following components:

pbin

array of bins in barycentric coordinates.

Nobs

number of forecasts in each bin.

obar

mean onservation associated with each forecast bin.

score

score associated with each forecast bin.

unc

uncertainty associated with each forecast bin.

rel

reliability associated with each forecast bin.

res

resolution associated with each forecast bin.

scorebar

overall score.

uncbar

overall uncertainty.

relbar

overall reliability.

resbar

overall resolution.

ncirc

number of bins along each side of triangle.

p

input forecast data.

o

input observation data.

assigned

index of bin assigned to each forecast.

L

scoring matrix used.

hexc

array of hexagon centres.

q

climatology.

pk

forecasts set to centre of each bin (tverify) or recalibrated (tgetcal)

ok

mean observations corresponding to forecasts pk

pars

parameters in calibration (tgetcal only).

opt

details of calibration (tgetcal only ).

f

calibration function (tgetcal only, for use with tcalibrate).

Author(s)

Tim Jupp

References

Jupp TE, Lowe R, Stephenson DB, Coelho CAS (2012) On the visualization, verification and recalibration of ternary probabilistic forecasts, Philosophical Transactions of the Royal Society, volume 370, pages 1100-1120.

http://rsta.royalsocietypublishing.org/content/370/1962/1100.full

http://arxiv.org/abs/1103.1303

Examples

data(foot)                            # get football betting data
tv   <- tverify(p=foot$p,o=foot$o)    # get verification info
plot(tv)                              # plot verification info