fred (version 0.3.1)

fred_series: Fetch observations for one or more FRED series

Description

The main function in the package. Downloads time series observations from FRED and returns a tidy data frame. Multiple series can be fetched in a single call, in either long or wide format.

Usage

fred_series(
  series_id,
  from = NULL,
  to = NULL,
  units = "lin",
  transform = NULL,
  frequency = NULL,
  aggregation = "avg",
  format = c("long", "wide"),
  cache = TRUE
)

Value

A fred_tbl (a data.frame subclass that prints with a one-line provenance header). In long format, columns are date, series_id, value. In wide format, columns are date plus one numeric column per series.

Arguments

series_id

Character. One or more FRED series IDs (e.g. "GDP", c("GDP", "UNRATE", "CPIAUCSL")).

from

Optional start date. Character ("YYYY-MM-DD") or Date.

to

Optional end date. Character ("YYYY-MM-DD") or Date.

units

Character. Raw FRED units code. Default "lin" (levels). Mutually exclusive with transform.

transform

Character. Readable transformation name. See Details.

frequency

Character. Frequency aggregation. One of "d" (daily), "w" (weekly), "bw" (biweekly), "m" (monthly), "q" (quarterly), "sa" (semiannual), "a" (annual), or NULL (native frequency, the default).

aggregation

Character. Aggregation method when frequency is specified. One of "avg" (default), "sum", or "eop" (end of period).

format

Character. "long" (default) returns one row per (series_id, date). "wide" returns one row per date with one column per series.

cache

Logical. If TRUE (the default), results are cached locally and returned from the cache on subsequent calls. Set to FALSE to force a fresh download from the API.

Details

FRED supports server-side unit transformations via the units argument. This avoids the need to compute growth rates or log transforms locally. For readability you can pass transform instead of units:

• "level", "raw" -levels (the default)

• "diff", "change" -change from previous period

• "yoy_diff" -change from one year ago

• "qoq_pct", "mom_pct", "pop_pct" -percent change from previous period

• "yoy_pct" -percent change from one year ago

• "annualised", "qoq_annualised" -compounded annual rate of change

• "log" -natural log

• "log_diff" -continuously compounded rate of change

• "log_diff_annualised" -continuously compounded annual rate

Raw FRED units codes ("lin", "chg", "ch1", "pch", "pc1", "pca", "cch", "cca", "log") are also accepted.

See Also

Other series: fred_info(), fred_search(), fred_updates(), fred_vintages()

Examples

# \donttest{
op <- options(fred.cache_dir = tempdir())
try({
  # Single series
  gdp <- fred_series("GDP")

  # Multiple series, long format
  macro <- fred_series(c("GDP", "UNRATE", "CPIAUCSL"))

  # Multiple series, wide format
  macro_w <- fred_series(c("GDP", "UNRATE"), format = "wide")

  # Readable transformation: year-on-year percent change
  gdp_growth <- fred_series("GDP", transform = "yoy_pct")

  # Aggregate daily to monthly
  rates <- fred_series("DGS10", frequency = "m")
})
options(op)
# }