calc_mtl_index: Calculate the mean Trophic Level

In andybeet/indexPPR: Utilities to create ecosystem overfishing indices for the NEFSC State of the Ecosystem report

Description

mean Trophic Level is calculated from a time series of landings: It is the sum of the species Trophic levels #' weighted by their landings #'

Usage

calc_mtl_index(catch, speciesTL, speciesCode = "NESPP3")

Arguments

speciesTL	dataframe. m x anything. Species codes and trophic level for the most abundantly caught species. One column must be named NESPP3 and another Troph
speciesCode	Character string. The name of the column that holds the speciesCodes. Default = "NESPP3".
data	dataframe. n x anything. Data containing the total catch by each species in each year. A complete grid of year by species must be passed. Columns must be named YEAR,NESPP3,catch.

Value

Data frame:

YEAR	Year of the index
INDEX	Value of the index

andybeet/indexPPR documentation built on March 18, 2021, 12:33 p.m.