def read_file(filename):
    """
    Reads in the file I created manually (by recompiling and adding timers)
    
    Not used any more but left for historical reasons (the first 'speedup'
    plots were generated with this function)
    """
    dtype = np.dtype([('same_cell', np.int32),
                      ('N1', np.int),
                      ('N2', np.int),
                      ('time', np.float)
                      ])
    if pd is not None:
        timings = pd.read_csv(filename, header=None,
                              engine="c",
                              dtype={'same_cell': np.int32,
                                     'N1': np.int,
                                     'N2': np.int,
                                     'time': np.float},
                              index_col=None,
                              names=['same_cell', 'N1', 'N2', 'time'],
                              delim_whitespace=True)
    else:
        timings = np.loadtxt(filename, dtype=dtype)
    return timings
Reads in the file I created manually (by recompiling and adding timers)
    
    Not used any more but left for historical reasons (the first 'speedup'
    plots were generated with this function)