One line TL = intercept + slope * <Type> per species and length type, for
restating a length measured on fork, standard or another length type as total
length. enrich_taxa() restates the FishBase lengths at maturity and optimum
with it, so a survey that converts its own lengths with the same table puts
both sides of the size-at-maturity comparison on one basis.
Arguments
- expanded
A table as returned by
expand_taxonomic_info().- version
FishBase / SeaLifeBase release to read. See
resolve_db_version().
Value
A tibble with one row per SpecCode, server and Type (the length
type converted from, e.g. "FL"), carrying the intercept and slope of
the conversion. Species or types with no published fit are absent.
Details
Every length type is read from the POPLL table, and each fit is oriented so
that total length is the response (see get_length_length_coeffs() for the
direction of the table). Where a species has several fits for one type, the
median intercept and the median slope are kept; identical fits published
twice count once.
Examples
if (FALSE) { # \dontrun{
taxa <- data.frame(alpha3_code = "YFT", scientific_name = "Thunnus albacares")
taxa |>
expand_taxonomic_info() |>
get_tl_conversions()
} # }