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qfasar: Quantitative Fatty Acid Signature Analysis in R

Software Download [176KB] | Metadata | AK Science Portal | Project Site | Date Range: 2016 - 2016

An implementation of Quantitative Fatty Acid Signature Analysis (QFASA) in R. QFASA is a method of estimating the diet composition of predators. The fundamental unit of information in QFASA is a fatty acid signature (signature), which is a vector of proportions describing the fatty acid composition of adipose tissue. Signature data from at least one predator and from samples of all potential prey types are required. Calibration coefficients, which adjust for the differential metabolism of individual fatty acids by predators, are also required. Given those data inputs, a predator signature is modeled as a mixture of potential prey signatures and its diet estimate is obtained as the mixture that minimizes a measure of distance between the observed and modeled signatures. A variety of estimation options, goodness-of-fit diagnostic procedures to assess the suitability of estimates, and simulation capabilities are implemented. Please refer to the package vignette and the documentation files for individual functions for details and references.

Author(s): Bromaghin, J. F.

Suggested Citation:
Bromaghin, J. F., 2016, qfasar: Quantitative Fatty Acid Signature Analysis in R: U.S. Geological Survey software release,

Referenced Publication(s):
Bromaghin, J. F. 2017. qfasar: quantitative fatty acid signature analysis with R. Methods in Ecology and Evolution 8(9):1158-1162. doi:10.1111/2041-210X.12740

DataID: 81 | doi:10.5066/F71G0JC9 | Date Posted Online: 2016-08-29 | Last Updated: 2019-07-29 12:41:40