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Calculate strata area

StrataAreas.fn.Rd

Calculate the area of your strata desired strata using the SA3_v2021.1.rda file (included with this package and accessible via utils::data("SA3_v2021.1")). Default areas are available for each of 1756 combinations of latitude and depth. Latitude breaks must fall on 0.5 degree breaks from 32.5 to 49.0 and depth breaks must be from the set (55, 75, 100, 125, 155, 183, 200, 250, 300, 350, 400, 450, 500, 549, 600, 700, 800, 900, 1000, 1100, 1200, 1280), where the unevenly spaced values are due to depth boundaries associated with the strata used in the survey sampling design. A latitude break at 40.166667 has also been added to allow strata split at that common management boundary near Cape Mendocino.

Usage

StrataAreas.fn(
  strat.df,
  df = get(utils::data("SA3_v2021.1", overwrite = TRUE, package = "nwfscSurvey"))
)

Arguments

strat.df

A data frame describing the strata names and boundaries. Boundaries are determined by latitude and bottom depth with Latitude_dd.1 and Latitude_dd.2 being the low and high bound for north to south and Depth_m.1 and Depth_m.2 being the low and high bound for east to west. A column of area can also be included if users want this column to be located in a certain order within the data frame, but it is not necessary.

df

The stored data frame or a personally created data frame that is used to calculate areas for the West Coast stratifications. The default data frame can be accessed using utils::data("SA3_v2021.1").

Value

Returns the strat.df with entries in the area column containing the area (square km) for each strata.

See also

See CreateStrataDF.fn for a wrapper to this function.

Author

Chantel Wetzel and Kelli Johnson

Examples

areaexample <- StrataAreas.fn(data.frame(
  name = LETTERS[1:8],
  Latitude_dd.2 = c(49, 49, 49, 45, 45, 40.5, 40.5, 40.5),
  Latitude_dd.1 = c(45, 45, 40.5, 40.5, 40.5, 34.5, 34.5, 34.5),
  Depth_m.1 = c(183, 549, 900, 183, 549, 183, 549, 900),
  Depth_m.2 = c(549, 900, 1280, 549, 900, 549, 900, 1280)
))
# setNames(round(areaexample[["area"]], 0), areaexample[["name"]])
#    A    B    C    D    E    F    G    H
# 5829 4024 9259 6211 5264 6952 7801 8059