getWLpars: Calculate weight-length relationship parameters

In nwfsc-assess/PacFIN.Utilities: Generate fishery composition data from PacFIN data for the NWFSC

Calculate weight-length relationship parameters

Description

Estimate parameters of the weight-length relationship for each sex and all sexes combined, where the latter includes unsexed fish.

Usage

getWLpars(
  data,
  col.length = "lengthcm",
  col.weight = "weightkg",
  verbose = TRUE
)

Arguments

data	A data frame containing empirical weights and lengths from sampled fish. Sexes should be available in the column sex or SEX.
col.length	A numeric or character value specifying the column to use in data for length information. These lengths are assumed to be in centimeters. The default value is lengthcm, which is added to a data set automatically when running cleanPacFIN.
col.weight	A numeric or character value specifying the column to use in data for weight information. These weights are assumed to be in kilograms The default value is weightkg, which is added to a data set automatically when running cleanPacFIN. Using kilograms is the default because Stock Synthesis assumes the weight-length parameters are calculated using centimeters and kilograms. The reported values are easily scaled to give you results in grams if you wish to have more standard parameter estimates.
verbose	A logical specifying if output should be written to the screen or not. Good for testing and exploring your data but can be turned off when output indicates information that you already know. The printing of output to the screen does not affect any of the returned objects. The default is to always print to the screen, i.e., verbose = TRUE.

Value

A data frame of weight-length parameters by sex. Parameters A and B are in the appropriate units to input into Stock Synthesis Wtlen_1_Fem and Wtlen_2_Fem, or Wtlen_1_Mal and Wtlen_1_Mal, parameters in the control file. Values of NA are returned for models that did not have enough data to properly estimate the parameters. This will happen when there are no females in your data set, for example.

Author(s)

Kelli F. Johnson

nwfsc-assess/PacFIN.Utilities documentation built on March 19, 2024, 11:54 p.m.