zoo (version 0.2-0)

merge.zoo: Merge Two or More zoo Objects

Description

Merge two zoo objects by common indexes (times), or do other versions of database "join" operations.

Usage

## S3 method for class 'zoo':
merge(\dots, all = TRUE, fill = NA, suffixes = NULL)

Arguments

...

two or more objects of class "zoo".

all

logical vector of the same length as the number of "zoo" objects which should be merged (otherwise expanded). All indexes (times) of the objects corresponding to TRUE are included, for those corresponding to FALSE only the indexes

fill

an element for filling the gaps in merged "zoo" objects which can arise when all = TRUE and some zoo arguments have some index values not in all other zoo arguments.

suffixes

character vector of the same length as the number of "zoo" objects that specifies the suffixes to be used for making the merged column names unique.

Value

• An object of class "zoo".

Details

The indexes of different "zoo" objects can be of different classes and are coerced to one class in the resulting object (with a warning).

See Also

zoo

Examples

## simple merging
x.date <- as.POSIXct(paste("2003-02-", c(1, 3, 7, 9, 14), sep = ""))
x <- zoo(rnorm(5), x.date)

y1 <- zoo(matrix(1:10, ncol = 2), 1:5)
y2 <- zoo(matrix(rnorm(10), ncol = 2), 3:7)

## using arguments `fill' and `suffixes'
merge(y1, y2, all = FALSE)
merge(y1, y2, all = FALSE, suffixes = c("a", "b"))

merge(x, y1, y2, all = TRUE)
merge(x, y1, y2, all = TRUE, fill = 0)


## extend an irregular series to a regular one:
# create a constant series
z <- zoo(1, seq(4)[-2])
# create a series with zero columns
z0 <- zoo(, 1:4)[,-1]
# do the extension
merge(z, z0)
# same but with zero fill
merge(z, z0, fill = 0)