# Aggregate Time Series

### Description

Convert series to quarterly or annual.

### Usage

1 2 3 |

### Arguments

`x` |
a tframed object. (Only montly is currently working) |

`FUN` |
the function to use for aggregating. |

`na.rm` |
Logical indicating if |

`foldFrom` |
a date which is used to determine the end of weeks. |

`periodicity` |
the number of periods in a week. |

`...` |
additional arguments passed to |

### Details

Functions `as.quarterly`

and `as.annually`

uses aggregate, but
shifts the data to match usual economic and
financial quarters or years (whereas aggregate simply groups together a number
of periods corresponding to the new frequency starting with the first
observation). These functions should give the same result as
aggregate if the data starts and ends on quarter (annual) boundaries.
If the data does not start and end on quarter (annual) boundaries
then `NA`

will be put in where
data is incomplete, and the quarter (year) removed if `na.rm=TRUE`

.

Monthly to annual gives the aggregate by converting first to quarterly, which is not exactly correct.

To weekly by `periodicity`

groupings from `foldFrom`

.
Partial weeks in the beginning or end are padded with `NA`

and
dropped if `na.rm=FALSE`

.
(as.weekly has been tested only with daily 7 day weeks.)

### Value

time series

### See Also

`tfwindow`

`aggregate`

### Examples

1 2 3 4 5 6 7 8 9 | ```
z <- ts(1:10, start = c(1999,2), frequency=4)
as.annually(z)
as.annually(z, na.rm=TRUE)
z <- ts(1:30, start = c(1999,2), frequency=12)
as.annually(z)
as.annually(z, na.rm=TRUE)
as.quarterly(z)
as.quarterly(z, na.rm=TRUE)
``` |