Custom Total row

[vvvvvvizard]

I have a straight table with Multiple expression. When i click on a button i want the Total Column which is the first row on the top to show the sum of total , when i click another button i want to see the average of the Column for certain columns . 

[pradosh_thakur · Accepted solution]

button1 -> on click ->set variable 1 = 1 and set variable 2 =0
button2 -> on click -> set variable 1 = 0 and set variable 2 =1

in the expression
=if (dimensionality=0,if( $(variable 2) = 1 , avgexpression ,sum expression), your expression)