TP_FP_FN_avg_sim        Find best matches (by cosine similarity) of a
                        set of mutational signatures to a set of
                        reference mutational signatures.
find_best_reconstruction_QP
                        Find "best" reconstruction of a target
                        signature or spectrum from a set of signatures.
match_two_sig_sets      Find an optimal matching between two sets of
                        signatures subject to a maximum distance.
optimize_exposure_QP    Quadratic programming optimization of signature
                        activities
plot_exposure           Plot exposures in multiple plots, with each
                        plot showing exposures for a manageable number
                        of samples.
plot_exposure_to_pdf    Plot exposures in multiple plots to a single
                        PDF file, with each plot showing exposures for
                        a manageable number of samples.
read_exposure           Read an exposure matrix from a file.
sig_dist_matrix         Compute a matrix of distances / similarities
                        between two sets of signatures.
sort_exposure           Sort columns of an exposure matrix based on the
                        number of mutations in each sample (column).
write_exposure          Write an exposure matrix to a file.
