Quantity: Calculate abundance in the strata

In StoXProject/RstoxBase: Base StoX Functions

Calculate abundance in the strata

Description

This function calculates abundance as the product of density and stratum area

Usage

Quantity(MeanDensityData, StratumAreaData)

Arguments

MeanDensityData	The MeanDensityData data.
StratumAreaData	The StratumAreaData data.

Details

The function merge the MeanDensityData with the StratumAreaData by Stratum and calculates the abundance as the product of density (number by square nautical miles) and area (square nautical miles). For acoustic-trawl estimates the abundance is calculated by Stratum, Layer, Beam, SpeciesCategory and IndividualTotalLength. In swept-area estimates the abundance is calculated by Stratum, Layer, SpeciesCategory and IndividualTotalLength

For swept-area estimates the density calculated by SweptAreaDensity can be given as "AreaWeightDensity" (as indicated by the column DensityType). In this case the Biomass column and not the Abundance column is populated in the output QuantityData from this function. The biomass is given in kilogram in this case, as Density is in kilogram per square nautical mile if DensityType = "AreaWeightDensity". This is different from the Biomass column of SuperIndividualsData, which is in gram, as it is generated from IndividualRoundWeight which is in gram.

Value

An object of StoX data type QuantityData. The QuantityData contains both an Abundance and a Biomass column, but only one of these can be populated.

See Also

SuperIndividuals for distributing Abundance to individuals.

StoXProject/RstoxBase documentation built on Nov. 6, 2024, noon