title: How display particular column summation in footer in ag-grid
body: <p><a href="https://i.stack.imgur.com/fsbWw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fsbWw.png" alt="enter image description here"></a>How to Display total sum of particular column at in footer of ag-grid table.
  for example if i have column name salary in ag-grid table then i want to show total salary sum at the bottom of grid as display in following screen.</p>