code: public void updateColumn(int j, VectorFunction function) {
          VectorIterator it = iteratorOfColumn(j);
  
          while (it.hasNext()) {
              double x = it.next();
              int i = it.index();
              it.set(function.evaluate(i, x));
          }
      }
docs: Updates all elements of the specified column in this matrix by applying given {@code function}.
  
  @param j the column index
  @param function the vector function