def calc_centers(edges):
    """
    Simple method for returning centers from an array of bin edges. Calculates center between each point as difference between containing edges. 
    Example, plt.plot(bicorr.centers(edges),counts,'.k')
    Serves as a shortcode to first producing array of bin centers.
    
    Parameters
    ----------
    edges : ndarray
        Array of bin edges
    
    Returns
    -------
    centers : ndarray
        Array of bin edges
    """
    return (edges[:-1]+edges[1:])/2