code: def show_gene_expression(self, gene, avg=True, axes=None, **kwargs):
          
  
          all_gene_names = np.array(list(self.adata.var_names))
          cell_names = np.array(list(self.adata.obs_names))
          all_cell_names = np.array(list(self.adata_raw.obs_names))
  
          idx = np.where(all_gene_names == gene)[0]
          name = gene
          if(idx.size == 0):
              print(
                  "Gene note found in the filtered dataset. Note that genes "
                  "are case sensitive.")
              return
  
          if(avg):
              a = self.adata.layers['X_knn_avg'][:, idx].toarray().flatten()
  
              if a.sum() == 0:
                  a = np.log2(self.adata_raw.X[np.in1d(
                      all_cell_names, cell_names), :][:,
                                                  idx].toarray().flatten() + 1)
          else:
              a = np.log2(self.adata_raw.X[np.in1d(
                  all_cell_names, cell_names), :][:,
                                                  idx].toarray().flatten() + 1)
  
          if axes is None:
              plt.figure()
              axes = plt.gca()
  
          self.scatter(c=a, axes=axes, **kwargs)
          axes.set_title(name)
docs: Display a gene's expressions.
  
          Displays a scatter plot using the SAM projection or another input
          projection with a particular gene's expressions overlaid.
  
          Parameters
          ----------
          gene - string
              a case-sensitive string indicating the gene expression pattern
              to display.
  
          avg - bool, optional, default True
              If True, the plots use the k-nearest-neighbor-averaged expression
              values to smooth out noisy expression patterns and improves
              visualization.
  
          axes - matplotlib axis, optional, default None
              Plot output to the specified, existing axes. If None, create new
              figure window.
  
          **kwargs - all keyword arguments in 'SAM.scatter' are eligible.