code: def _set_lim_and_transforms(self):
          
          # There are three important coordinate spaces going on here:
          #
          #    1. Data space: The space of the data itself
          #
          #    2. Axes space: The unit rectangle (0, 0) to (1, 1)
          #       covering the entire plot area.
          #
          #    3. Display space: The coordinates of the resulting image,
          #       often in pixels or dpi/inch.
  
          # This function makes heavy use of the Transform classes in
          # ``lib/matplotlib/transforms.py.`` For more information, see
          # the inline documentation there.
  
          # The goal of the first two transformations is to get from the
          # data space to axes space.  It is separated into a non-affine
          # and affine part so that the non-affine part does not have to be
          # recomputed when a simple affine change to the figure has been
          # made (such as resizing the window or changing the dpi).
  
          # 3) This is the transformation from axes space to display
          # space.
          self.transAxes = BboxTransformTo(self.bbox)
  
          # Now put these 3 transforms together -- from data all the way
          # to display coordinates.  Using the '+' operator, these
          # transforms will be applied "in order".  The transforms are
          # automatically simplified, if possible, by the underlying
          # transformation framework.
          #self.transData = \
          #    self.transProjection + self.transAffine + self.transAxes
          self.transData = self.GingaTransform()
          self.transData.viewer = self.viewer
  
          # self._xaxis_transform = blended_transform_factory(
          #         self.transData, self.transAxes)
          # self._yaxis_transform = blended_transform_factory(
          #         self.transAxes, self.transData)
          self._xaxis_transform = self.transData
          self._yaxis_transform = self.transData
docs: This is called once when the plot is created to set up all the
          transforms for the data, text and grids.