code: def add_colour_scaled_points(self, longitude, latitude, data, shape='s',
                                   alpha=1.0, size=20, norm=None, overlay=False):
          
          if not norm:
              norm = Normalize(vmin=np.min(data), vmax=np.max(data))
          x, y, = self.m(longitude, latitude)
          mappable = self.m.scatter(x, y,
                                    marker=shape,
                                    s=size,
                                    c=data,
                                    norm=norm,
                                    alpha=alpha,
                                    linewidths=0.0,
                                    zorder=4)
          self.m.colorbar(mappable=mappable, fig=self.fig, ax=self.ax)
          if not overlay:
              plt.show()
docs: Overlays a set of points on a map with a fixed size but colour scaled
          according to the data
  
          :param np.ndarray longitude:
              Longitude
          :param np.ndarray latitude:
              Latitude
          :param np.ndarray data:
              Data for plotting
          :param str shape:
              Marker style
          :param float alpha:
              Sets the transparency of the marker (0 for transparent, 1 opaque)
          :param int size:
              Marker size
          :param norm:
              Normalisation as instance of :class: matplotlib.colors.Normalize