bandtest {wsyn}

Aggregate significance across a timescale band

Description

Computes the aggregate significance of coherence (coh) or of a wavelet linear model test object (wlmtest) across a timescale band, accounting for non-independence of timescales. Also gets the average phase across the band, in the case of coherence.

Usage

bandtest(object, ...)

## Default S3 method:
bandtest(object, ...)

## S3 method for class 'coh'
bandtest(object, band, ...)

## S3 method for class 'wlmtest'
bandtest(object, band, ...)

Arguments

object

An object of class coh or wlmtest, must have a non-NA signif slot

...

Passed from the generic to specific methods. Not currently used.

band

A length-two numeric vector indicating a timescale band

Value

bandtest returns an object of the same class as its first input but with a bandp slot added. Or if there was already a bandp slot, the output has a bandp slot with an additional row. For a coh object, the bandp slot is a data frame with four columns, the first two indicating the timescale band and the third an associated p-value for the test of coherence over that band. The fourth column is the average phase over the band. For a wlmtest object, the result is only the first three of the above columns.

Author(s)

Thomas Anderson, [e-mail], Jon Walter, [e-mail]; Lawrence Sheppard, [e-mail]; Daniel Reuman, [e-mail]

References

Sheppard, L.W., et al. (2016) Changes in large-scale climate alter spatial synchrony of aphid pests. Nature Climate Change. DOI: 10.1038/nclimate2881

See Also

coh, wlm, wlmtest, browseVignettes("wsyn")

Examples

#Example for a coh object
times<-(-3:100)
ts1<-sin(2*pi*times/10)
ts2<-5*sin(2*pi*times/3)
artsig_x<-matrix(NA,11,length(times)) #the driver
for (counter in 1:11)
{
  artsig_x[counter,]=ts1+ts2+rnorm(length(times),mean=0,sd=1.5)
}
times<-0:100
artsig_y<-matrix(NA,11,length(times)) #the driven
for (counter1 in 1:11)
{
  for (counter2 in 1:101)
  {
    artsig_y[counter1,counter2]<-mean(artsig_x[counter1,counter2:(counter2+2)])
  }
}
artsig_y<-artsig_y+matrix(rnorm(length(times)*11,mean=0,sd=3),11,length(times))
artsig_x<-artsig_x[,4:104]
artsig_x<-cleandat(artsig_x,times,1)$cdat
artsig_y<-cleandat(artsig_y,times,1)$cdat
cohobj<-coh(dat1=artsig_x,dat2=artsig_y,times=times,norm="powall",sigmethod="fast",nrand=1000,
            f0=0.5,scale.max.input=28)
cohobj<-bandtest(cohobj,c(2,4))
  
#Example for a wlmtest object - see vignette