edwards: edwards

In ldbk/Rplanktonanalytic: What the Package Does (One Line, Title Case)

Description

This function computes the timing of a seasonal peak using Edwards and Richardson formula

Usage

edwards(value, time)

Arguments

value	a numerical vector of values (abundances...)
time	a numerical vector of temporal units (month, week...)

Value

a numerical value corresponding to the timing of the seasonal peak in time unit corresponding the time vector

Details

The seasonal peak timing is defined throughout the entire growing season using the time scale coordinate (number of the month, week, day...) of the centre of gravity of the area below the plot of the corresponding values.

For monthly data the seasonal peak timing T is:

T= \frac{∑_{i=1}^{12}M.x_m}{∑_{i=1}^{12}x_m}

with x_m is the abundance in month M (January=1,...Decembre=12).

Author(s)

Laurent Dubroca

Source

Edwards, M Richardson A.J. Impact of climate change on marine pelagic phenology and trophic mismatch. Nature, 2004, 430, 881-884. http://dx.doi.org/10.1038/nature02808.

Examples

## Not run: 
time<-1:12
value<-c(0,0,1,2,5,7,3,0,0,0,0,0)
edwards(time,value)


## End(Not run)

ldbk/Rplanktonanalytic documentation built on June 29, 2021, 9:23 p.m.