GastrosomaticIndex {dietr}

Calculates Gastro-somatic Index (AKA Fullness Index, Index of fullness)

Description

This function calculates Gastro-somatic fullness, the relationship between stomach weight and body weight to assess fullness.

Usage

GastrosomaticIndex(StomachData, Calc.Vacuity = FALSE)

Arguments

StomachData

Object of class data frame containing stomach data. The data frame must be set up as follows. The first column should contain the specimen identifier, the second column the stomach weight, and the third column the weight of the specimens.

Calc.Vacuity

Logical. Should the vacuity index also be calculated? Default is FALSE.

Value

Object of Class List of length 2 or 3. If Calc.Vacuity = FALSE, a list of length two is returned containing a named vector of individual specimen gastro-somatic index as well as a numeric vector length of 1 containing the mean gastro-somatic index. If Calc.Vacuity = TRUE, an additional numeric vector of length 1 is returned containing the calculated vacuity index.

Author(s)

Samuel Borstein

References

Hureau J-C. 1970. Biologie comparee de quelques poissons antarctiques (Nototheniidae). Bulletin de l'Institut Oceanographique de Monaco 68:1-244.

See Also

VacuityIndex

Examples

data(SebastesStomachs)#load example data
#Calculate the Gastro-somatic Index
my.GSI <- GastrosomaticIndex (StomachData = SebastesStomachs)
#Calculate the Gastro-somatic Index and Vacuity Index
my.GSI <- GastrosomaticIndex (StomachData = SebastesStomachs, Calc.Vacuity = TRUE)