R: Maximum spell length

spell.length.max {climdex.pcic} | R Documentation

## Maximum spell length

### Description

This function returns the longest string of days which exceed or are below the given threshold.

### Usage

    spell.length.max(daily.prec, date.factor, threshold, op, spells.can.span.years)

### Arguments

`daily.prec` | Data to compute index on.
`date.factor` | Date factor to split by.
`threshold` | The threshold to compare to.
`op` | The operator to use to compare data to threshold.
`spells.can.span.years` | Whether spells can span years.

### Details

This routine compares data to the threshold using the given operator, generating a series of TRUE or FALSE values. It then computes the lengths of sequences of TRUE values (spells) and chooses the longest spell in each period (as defined by date.factor).

The `spells.can.span.years` option controls whether spells must always terminate at the end of a period, or whether they may continue until the criteria ceases to be met or the end of the data is reached. The default for fclimdex is TRUE.

### Value

A timeseries of maximum spell lengths for each period.

### See Also

`climdex.cdd`.

### Examples

    prec.dat <- c(0.1, 3.0, 4.3, 1.9, 1.3, 6.0, 0, 0, 4.0, 1)
    phony.date.factor <- factor(rep(1:2, each=5))

    ## With spells spanning years...
    cwd <- spell.length.max(prec.dat, phony.date.factor, 1, ">=", TRUE)

    ## Without spells spanning years...
    altcwd <- spell.length.max(prec.dat, phony.date.factor, 1, ">=", FALSE)

[Package climdex.pcic version 1.1-11 Index]