append_ilr_coords       Add ILR coordinates to a data.frame containing
                        composition variables
check_input_args        Sanity checks for arguments passed to
                        predict_delta_comps()
check_strictly_positive_vals
                        Check if compositional variable are strictly
                        greater than 0
cols_exist              Check whether columns exist in a data.frame
compare_two_lm          Statistical test of the collective significance
                        of the ilr variables
create_comparison_matrix
                        Creates row-wise perturbations of compositions
                        from the mean composition
create_v_mat            Create ilr basis matrix (V)
extract_lm_quantities   Extract critical quantities from a lm object
                        (for confidence interval calculations)
fairclough              Data from Fairclough (2017). Fitness, fatness
                        and the reallocation of time between children's
                        daily movement behaviours: an analysis of
                        compositional data
fat_data                Randomly generated data to simulate child fat
                        percentage regressed on time-use compositional
                        data
fit_lm                  fit linear model based on input data.frame
is_deltacomp_obj        Is object that is returned from
                        'pred_delta_comps()'?
is_lm_mod               Is object that is returned from 'lm()'?
is_null_or_na           Catch NULL, empty and objects containing NAs
plot_delta_comp         Plot redistributed time-use predictions from
                        compositional ilr multiple linear regression
                        model fit
predict_delta_comps     Get predictions from compositional ilr multiple
                        linear regression model
print_ilr_trans         Print the ilr transformation of provided
                        composition parts to console
