verification (version 1.01)

attribute: Attribute plot

Description

An attribute plot illustrates the reliability, resolution and uncertainty of a forecast with respect to the observation. The frequency of binned forecast probabilities are plotted against proportions of binned observations. A perfect forecast would be indicated by a line plotted along the 1:1 line. Uncertainty is described as the vertical distance between this point and the 1:1 line. The relative frequency for each forecast value is displayed in parenthesis.

Usage

## S3 method for class 'default':
attribute(x, obar.i,  prob.y, obar = NULL, titl =
NULL, \dots)
## S3 method for class 'prob.bin':
attribute(x, \dots)

Arguments

x

A vector of forecast probabilities or a ``prob.bin'' class object produced by the verify function.

obar.i

A vector of observed relative frequency of forecast bins.

prob.y

Relative frequency of forecasts of forecast bins.

obar

Climatological or sample mean of observed events.

titl

Plot title.

...

Graphical parameters

References

Hsu, W. R., and A.H. Murphy, 1986: The attributes diagram: A geometrical framework for assessing the quality of probability forecasts. Int. J. Forecasting 2, 285-293. Wilks, D. S. (1995) Statistical Methods in the Atmospheric Sciences Chapter 7, San Diego: Academic Press.

See Also

verify

Examples

## Data from Wilks, table 7.3 page 246.
 y.i   <- c(0,0.05, seq(0.1, 1, 0.1))
 obar.i <- c(0.006, 0.019, 0.059, 0.15, 0.277, 0.377, 0.511, 
             0.587, 0.723, 0.779, 0.934, 0.933)
 prob.y<- c(0.4112, 0.0671, 0.1833, 0.0986, 0.0616, 0.0366,
            0.0303,  0.0275, 0.245, 0.022, 0.017, 0.203) 
 obar<- 0.162
 
attribute(y.i, obar.i, prob.y, obar, titl = "Sample Attribute Plot")  

## Function will work with a ``prob.bin'' class objects as well.
## Note this is a random forecast.
obs<- round(runif(100))
pred<- runif(100)

A<- verify(obs, pred, frcst.type = "prob", obs.type = "binary")

attribute(A, titl = "Alternative plot", xlab = "Alternate x label" )