code: def filter_genes_cv_deprecated(X, Ecutoff, cvFilter):
      
      if issparse(X):
          raise ValueError('Not defined for sparse input. See `filter_genes_dispersion`.')
      mean_filter = np.mean(X, axis=0) > Ecutoff
      var_filter = np.std(X, axis=0) / (np.mean(X, axis=0) + .0001) > cvFilter
      gene_subset = np.nonzero(np.all([mean_filter, var_filter], axis=0))[0]
      return gene_subset
docs: Filter genes by coefficient of variance and mean.
  
      See `filter_genes_dispersion`.
  
      Reference: Weinreb et al. (2017).