code: def remove_negative_entries(A):
      r
      A = A.tocoo()
  
      data = A.data
      row = A.row
      col = A.col
  
      """Positive entries"""
      pos = data > 0.0
  
      datap = data[pos]
      rowp = row[pos]
      colp = col[pos]
  
      Aplus = coo_matrix((datap, (rowp, colp)), shape=A.shape)
      return Aplus
docs: r"""Remove all negative entries from sparse matrix.
  
          Aplus=max(0, A)
  
      Parameters
      ----------
      A : (M, M) scipy.sparse matrix
          Input matrix
  
      Returns
      -------
      Aplus : (M, M) scipy.sparse matrix
          Input matrix with negative entries set to zero.