Quantitative Fatty Acid Signature Analysis


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Documentation for package ‘QFASA’ version 1.2.0

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QFASA-package QFASA: A package for Quantitative Fatty Acid Signature Analysis
AIT.dist Returns the distance between two compositional vectors using Aitchison's distance measure.
AIT.more Used to provide additional information on various model components evaluated at the optimal solution, i.e., using the QFASA diet estimates and Aitchison distance measure.
AIT.obj Used in 'solnp()' as the objective function to be minimized when Aitchison distance measure is chosen.
backward.elimination Returns diet estimates corresponding to a sample of predators based on a backward elimination algorithm that chooses the prey species to be included in the modelling.
bal.diet.data Sample example of balanced repeatability diet estimates data with only two repeated measurements per predator.
CC Fatty acid calibration coefficients.
chisq.CA Called by 'create.d.mat()' to compute the chi-square distance.
chisq.dist Returns the distance between two compositional vectors using the chi-square distance.
comp.rep Repeatability in Diet Estimates
conf.meth Confidence Intervals for Diet Proportions
create.d.mat Called by 'testfordiff.ind.boot.fun()' to create a matrix of distances.
CS.more Used to provide additional information on various model components evaluated at the optimal solution, i.e., using the QFASA diet estimates and chi-square distance measure.
CS.obj Used in 'solnp()' as the objective function to be minimized when chi-square distance measure is chosen. Unlike 'AIT.obj()' and 'KL.obj()', does not require modifying zeros.
FAset List of fatty acids used in sample prey and predator data sets, 'preyFAs' and 'predatorFAs' respectively.
forward.selection Returns diet estimates corresponding to a sample of predators based on a forward selection algorithm that chooses the prey species to be included in the modelling.
KL.dist Returns the distance between two compositional vectors using Kullback-Leibler distance measure.
KL.more Used to provide additional information on various model components evaluated at the optimal solution, i.e., using the QFASA diet estimates and Kullback-Leibler distance measure.
KL.obj Used in 'solnp()' as the objective function to be minimized when Kullback-Leibler distance measure is chosen.
MEANmeth Returns the multivariate mean FA signature of each prey group entered into the QFASA model. Result can be passed to prey.mat in 'p.QFASA()'.
mean_geometric Returns the geometric mean of a compositional vector
p.MLE Returns simplified MLE diet estimates corresponding to a sample of predators.
p.MUFASA Returns MUFASA diet estimates corresponding to a sample of predators.
p.QFASA Returns QFASA diet estimates corresponding to a sample of predators.
p.sim.QFASA Simultaneous estimation of diet composition and calibration coefficients
p.SMUFASA Simultaneous maximum unified fatty acid signature analysis
POOLVARmeth Computes within species variance-covariance matrices on transformed scaled, along with a pooled estimate.
predatorFAs Predator fatty acid signatures. Each predator signature is a row with fatty acid proportions in columns.
prey.cluster Produces a dendrogram using distances between the mean FA signatures of the prey types.
prey.on.prey Each prey fatty acid signature is systematically removed from the supplied prey database and its QFASA diet estimate is obtained by treating the individual as a predator.
preyFAs Prey fatty acid signatures. Each prey signature is a row with fatty acid proportions in columns.
pseudo.pred Generate a pseudo predator by sampling with replacement from prey database.
pseudo.pred.norm Generate a pseudo predator parametrically from multivariate normal distributions.
QFASA QFASA: A package for Quantitative Fatty Acid Signature Analysis
QFASA.const.eqn Returns 'sum(alpha)' and used in 'solnp()'.
split_prey Splits prey database into a simulation set (1/3) and a modelling set (2/3). Returns a list:
testfordiff.ind.boot Called by 'testfordiff.ind.pval()'.
testfordiff.ind.boot.fun Called by 'testfordiff.ind.boot()'.
testfordiff.ind.pval Test for a difference between two independent samples of compositional data. Zeros of any type are allowed.
unbal.diet.data Sample example of unbalanced repeatability diet estimates data with a max of two repeated measurements per predator.