docs: def addRasterPoints(self, xdata, repnum, plotname=None):
          """Add a list (or numpy array) of points to raster plot, 
          in any order.
  
          :param xdata: bin centers
          :param ydata: rep number 
          """
          if plotname is None:
              plotname = self.responsePlots.keys()[0]
          ydata = np.ones_like(xdata)*repnum
          self.responsePlots[plotname].appendData('raster', xdata, ydata)