bio15: bio15: Calculates precipitation seasonality

In ilyamaclean/climvars: Functions for calculating biologically meaningful climate variables

Description

bio15 is used to calculate precipitation seasonality, which is the standard deviation of weekly or monthly precipitation values as a percentage of the mean of those values.

Usage

bio15(prec, tme, method = "anuclim")

Arguments

prec	a vector of precipitation values, normally for one year (see details).
tme	a POSIXlt object representing the date and time of each prec value.
method	an optional character string describing the method used to calculate precipitation seasonality. Options include "anuclim" or unspecified (see details).

Details

If method is "anuclim", monthly precipitation is spline interpolated to a weekly time period and precipitation seasonality calculated using these values, replicating the method used by http://www.worldclim.org/. Otherwise, precipitation seasonality is calculated using yearly values.

If using anuclim method and data span more than one year, data are aggregated by unique month irrespective of year and one value returned. If method is left unspecified and data span more than one year, calculations will be performed on all data and a single value returned.

Value

a single numeric value representing precipitation seasonality.

See Also

the tmecreate() function can be used to create a POSIXlt object.

Examples

prec <- (10 * sin(c(0:364) * (pi / -360)) + rnorm(365) + 12)
tme <- tmecreate(2010, 24)
plot(prec~as.POSIXct(tme), type = "l", xlab = "Month", ylab = "Precipitation")
bio15(prec, tme, method="week")
bio15(prec, tme, method="month")

ilyamaclean/climvars documentation built on June 19, 2019, 2:22 p.m.