; the purpose of this function is to take as input a series of bin ; boundaries and return the bin centers ; created by Robert Lillis ((rlillis@ssl.Berkeley.edu) Function bin_centers, bin_edges nbins = n_elements (bin_edges) -1 return, bin_edges[0: nbins -1]+ 0.5*(bin_edges[1:*] -$ bin_edges [0: nbins -1]) end