docs: def scale_lim(lim,factor=1.05):
    r'''
  Scale limits to be 5% wider, to have a nice plot.
  
  :arguments:
  
    **lim** (``<list>`` | ``<str>``)
      The limits. May be a string "[...,...]", which is converted to a list.
  
  :options:
  
    **factor** ([``1.05``] | ``<float>``)
      Scale factor.
    '''
  
    # convert string "[...,...]"
    if type(lim) == str: lim = eval(lim)
  
    # scale limits
    D       = lim[1] - lim[0]
    lim[0] -= (factor-1.)/2. * D
    lim[1] += (factor-1.)/2. * D
  
    return lim