areaPermutation         Calculate Area Ratio (AR) of each feature's
                        time interval for all permutations
curveFitting            Fit longitudinal data
findSigInterval         Find significant time intervals
intervalArea            Calculate Area Ratio (AR) of each feature's
                        time interval
metalonda               Metagenomic Longitudinal Differential Abundance
                        Analysis for one feature
metalondaAll            Metagenomic Longitudinal Differential Abundance
                        Analysis for all Features
metalonda_test_data     Simulated data of OTU abundance for 2
                        phenotypes each has 5 subjects at 10
                        time-points
normalize               Normalize count matrix
permutation             Permute group labels
visualizeARHistogram    Visualize Area Ratio (AR) empirical
                        distribution
visualizeArea           Visualize significant time interval
visualizeFeature        Visualize Longitudinal Feature
visualizeFeatureSpline
                        Visualize the feature trajectory with the
                        fitted Splines
visualizeTimeIntervals
                        Visualize all significant time intervals for
                        all tested features
visualizeVolcanoPlot    Visualize log2 fold-change and significance of
                        each interval as volcano plot
