# Worsley.Likelihood.Ratio: Worsley's Likelihood Ratio test In climtrends: Statistical Methods for Climate Sciences

## Description

`WorsleyLikelihoodRatio` returns the result of Worsley's Likelihood Ratio test applied to a time series.

## Usage

 `1` ```WorsleyLikelihoodRatio(yearDF, datecol=1,valcol=2, returnZk=FALSE) ```

## Arguments

 `yearDF` dataframe with climate data `datecol` column with dates `valcol` column with values `returnZk` return calculated data Zk

## Value

The result of Worsley's Likelihood Ratio test.

Jose Gama

## Source

Wijngaard, J. B., Klein Tank, A. M. G. and K<c3><b6>nnen, G. P. (2003), Homogeneity of 20th century European daily temperature and precipitation series. Int. J. Climatol., 23: 679<e2><80><93>692. doi: 10.1002/joc.906

## References

Wijngaard, J. B., Klein Tank, A. M. G. and K<c3><b6>nnen, G. P. (2003), Homogeneity of 20th century European daily temperature and precipitation series. Int. J. Climatol., 23: 679<e2><80><93>692. doi: 10.1002/joc.906

## Examples

 `1` ```demo(demoWorsleyLR) ```

### Example output

```	demo(demoWorsleyLR)
---- ~~~~~~~~~~~~~

> # Worsley Likelihood Ratio
> # example based on:
> # TREND Tests in Excel Spreadsheet
> # eWater toolkit TREND Version 1.0.2
> # http://www.toolkit.net.au/Tools/TREND/documentation
>
> test1 <- matrix(c(1940,681,
+ 1941,3661,
+ 1942,8625,
+ 1943,2475,
+ 1944,573,
+ 1945,2794,
+ 1946,10190,
+ 1947,5143,
+ 1948,4139,
+ 1949,8945,
+ 1950,7295,
+ 1951,19883,
+ 1952,12119,
+ 1953,8772,
+ 1954,8848,
+ 1955,16309,
+ 1956,16254,
+ 1957,2303,
+ 1958,7671,
+ 1959,3985,
+ 1960,13742,
+ 1961,5333,
+ 1962,4859,
+ 1963,12381,
+ 1964,12137,
+ 1965,6075,
+ 1966,4669,
+ 1967,378,
+ 1968,7507,
+ 1969,3891,
+ 1970,13046,
+ 1971,12954,
+ 1972,2445,
+ 1973,14759,
+ 1974,20200,
+ 1975,16331,
+ 1976,6922,
+ 1977,6739,
+ 1978,11629,
+ 1979,7351,
+ 1980,2445,
+ 1981,9960,
+ 1982,10,
+ 1983,11786,
+ 1984,10214,
+ 1985,11216,
+ 1986,8393,
+ 1987,10005,
+ 1988,6896,
+ 1989,11632),ncol=2,byrow=TRUE)

> colnames(test1) <- c('year','data')

> WLR <- WorsleyLikelihoodRatio(test1,returnZk=TRUE)

> cat('Worsley Likelihood Ratio\n\nYear of change =',WLR\$YearChange,'\nV =',WLR\$V,'\nW =',WLR\$W)
Worsley Likelihood Ratio

Year of change = 1945
V = 0.3855236
W = 2.894757
> plot(test1[,1], WLR\$Zk ,type='l',xlab='',ylab='Worsley Likelihood Ratio')
```

climtrends documentation built on May 29, 2017, 11:58 p.m.