fasstr: add_seasons – R documentation

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add_seasons

Add a column of seasons

Description

Adds a column of seasons identifiers to a data frame with a column of dates called 'Date'. The length of seasons, in months, is provided using the seasons_length argument. As seasons are grouped by months the length of the seasons must be divisible into 12 with one of the following season lengths: 1, 2, 3, 4, 6, or 12 months. The start of the first season coincides with the start month of each year; 'Jan-Jun' for 6-month seasons starting with calendar years or 'Dec-Feb' for 3-month seasons starting with water year starting in December.

Usage

add_seasons(
  data,
  dates = Date,
  station_number,
  water_year_start = 1,
  seasons_length
)

Arguments

`data`	Data frame of daily data that contains columns of dates, flow values, and (optional) groups (e.g. station numbers). Leave blank if using `station_number` argument.
`dates`	Name of column in `data` that contains dates formatted YYYY-MM-DD. Only required if dates column name is not 'Date' (default). Leave blank if using `station_number` argument.
`station_number`	Character string vector of seven digit Water Survey of Canada station numbers (e.g. `"08NM116"`) of which to extract daily streamflow data from a HYDAT database. Requires `tidyhydat` package and a HYDAT database. Leave blank if using `data` argument.
`water_year_start`	Numeric value indicating the month (`1` through `12`) of the start of water year for analysis. Default `1`.
`seasons_length`	Numeric value indicating the desired length of seasons in months, divisible into 12. Required.

Value

A tibble data frame of the source data with additional column:

Season

season identifier labelled by the start and end month of the season

Examples

# Run if HYDAT database has been downloaded (using tidyhydat::download_hydat())
if (file.exists(tidyhydat::hy_downloaded_db())) {

# Add a column with four annual seasons starting in January
add_seasons(station_number = "08NM116",
            seasons_length = 4)

# Add a column with two annual seasons (of 6 months length) starting in October
add_seasons(station_number = "08NM116", 
            water_year_start = 10,
            seasons_length = 6)
            
}

fasstr

Analyze, Summarize, and Visualize Daily Streamflow Data

v0.3.2

Apache License 2.0

Authors

Jon Goetz [aut, cre] (<https://orcid.org/0000-0002-4993-1119>), Carl James Schwarz [aut], Robin Pike [ctb], Province of British Columbia [cph]

Initial release