Merge two time-indexed series using either the levels or the first differences of the second series where the series overlap.
mergeSeries(x, y, differences = FALSE, naLoses = FALSE)tis objects, or objects that can sensibly be coerced to
tis by as.tis.
if TRUE, the first differences of series are merged, and then
cumulatively summed. The default is FALSE.
if TRUE, NA values in y do not overwrite
corresponding values in x.
A tis object series with start and end dates that span those of
x and y. Where the series overlap, values from y
are used, except that if naLoses is TRUE, NA
values from y do not overwrite non-NA values in x.
x and y must have the same tif (ti frequency),
and the same number of column (if they are multivariate).