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Download and Aggregate Yearly Climate Data (Reduce Format)

Source: R/dl_yearly_single.R
smn_dl_yearly_single.Rd

Downloads daily data for an SMN station using smn_dl_daily_single() and aggregates to yearly values for one or more variables, with quality control based on an allowed fraction of missing days per year. The output is always in reduce (wide) format: one row per year with the requested variables as columns plus station metadata.

Usage

smn_dl_yearly_single(
  station,
  start_date = "1961-01-01",
  end_date = Sys.Date(),
  variables = "all",
  max_missing_frac = 0.2,
  aggregator = NULL,
  csv_file = NULL
)

Arguments

station

Character or numeric. SMN station code (e.g., "15101").

start_date

Character or Date. Start of the daily window (default "1961-01-01", inclusive).

end_date

Character or Date. End of the daily window (default Sys.Date(), inclusive).

variables

Character vector of variables to summarize. Any subset of c("prec","evap","tmax","tmin"). Use "all" to include all four (default "all").

max_missing_frac

Numeric in [0, 1]. Maximum allowed fraction of missing days per year to keep that year's aggregate for a variable (default 0.2). When the missing fraction exceeds the threshold, that yearly value is set to NA.

aggregator

Either:

  • NULL (default): uses sum for "prec","evap" and mean for "tmax","tmin", or

  • a single function (e.g., median) applied to all variables, or

  • a named list mapping variables to functions, e.g. list(prec = sum, evap = sum, tmax = mean, tmin = mean).

csv_file

Optional file path. If non-NULL, the result is written to CSV (row.names = FALSE) and also returned.

Value

A base data.frame in reduce (wide) format with columns: station, latitude, longitude, altitude, YEAR, <variables...>. If no data are available, returns an empty table with the same schema.

Details

Internally calls smn_dl_daily_single() with output_format = "full" to fetch daily data and station metadata. The missing-data rule is computed per year and per variable as #(NA) / #(days in year).

Examples

if (FALSE) { # \dontrun{
# All variables in reduce format (default)
y1 <- smn_dl_yearly_single(
  station = "15101",
  start_date = "2000-01-01",
  end_date   = "2005-12-31",
  variables  = "all"
)

# Subset of variables and custom aggregator
y2 <- smn_dl_yearly_single(
  station = "15101",
  start_date = "1990-01-01",
  end_date   = "1999-12-31",
  variables  = c("prec","tmax"),
  aggregator = list(prec = sum, tmax = median)
)
} # }