pooling | R Documentation |
Several pooling procedures can be applied to reduce the number of dependent droughts.
pool_ic(x, tmin = 5, ratio = 0.1) pool_it(x, tmin = 5) pool_ma(x, n = 10) pool_sp(x)
x |
an object of class |
tmin |
numeric vector of length one interpreted as the number of days between two droughts to be considered independent events. Two droughts are pooled if their inter-event time is less than |
ratio |
numeric vector of length. Specifies the minimum ratio of inter-event volume and precedent drought volume. Two droughts are pooled if the critical |
n |
numeric vector of length one determining the width of the smoothing window |
The inter-event criterion (pool_ic
) pools subsequent drought events if the inter-event time is less than tmin
and the ratio of the drought volume and the inter-event volume is less than a given ratio
. The function pool_it
is simply a wrapper around pool_ic(..., ratio = Inf)
.
Pooling by a moving average (pool_ma
) simply smooths the time series before finding drought events.
Using the Sequent Peak algorithm (pool_sp
), a drought lasts until its cumulative deficit volume is zero again.
an object of class deficit
(inherited from xts
), with an
additional column event.orig
.
find_droughts
, summary.deficit
data(ngaruroro) ng <- as.xts(ngaruroro) ng <- ng["1986::1990", ] drought <- find_droughts(ng) ic <- pool_ic(drought) summary(ic) ma <- pool_ma(drought) summary(ma) sp <- pool_sp(drought) summary(sp) plot(sp)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.