landings: Calculates the Landings per fished group
In dempseydanielle/marindicators: Marine Ecosystem and Fishing Pressure Indicators

Description Usage Arguments Details Value Author(s) References See Also Examples

This function calculates the commercial landings of predefined species groups for j areas and i years.

1	landings(land, groups, species.table = NULL, years)

`land`	A dataframe of commercial landings data with columns `YEAR`, `ID`, `SPECIES` and `CATCH`. `YEAR` indicates the year the landing was recorded, `ID` is an area code indicating where the landing was recorded, `SPECIES` is a numeric code indicating the species landed, and `CATCH` is the corresponding landed weight.
`groups`	A vector indicating the species group(s) for which to calculate the indicator. If `groups = "ALL"`, all species will be included; otherwise, each entry must be a character string matching the name of a column in `species.table`.
`species.table`	A table with at least one column, where the column names match the entries in `groups`, and the column entries are species codes from `land` indicating which species are included that group. `species.table` may also include columns for other species groups; these will be ignored. If `group = "ALL"`, this table is not required. Default is `species.table = NULL`.
`years`	A vector of years for which to calculate indicator.

Calculates the Landings of predefined species groups.

Returns a dataframe with columns ID and YEAR, and a column landings_group for each entry in groups.

If there is no data for a given year, the indicator value is set to 0.

Danielle Dempsey, Adam Cook Adam.Cook@dfo-mpo.gc.ca, Catalina Gomez, Alida Bundy

Bundy A, Gomez C, Cook AM. 2017. Guidance framework for the selection and evaluation of ecological indicators. Can. Tech. Rep. Fish. Aquat. Sci. 3232: xii + 212 p.

Other fishing pressure indicators: allPressure(), fishingPressure(), meanTLLandings(), speciesRichness()

# Compile data
data(land)
data(species.table)

# Species of interest
landings.groups <- c("ALL", "CLUPEIDS.L", "FLATFISH.L", "GROUNDFISH.L")

# Calculate indicators
landings(land, groups = landings.groups, species.table = species.table,
   years = c(2014:2019))