set analysis problem

[#1]

i have used this expresssion in my chart

if (dimension='Stock',sum({<calmonth=$(v_max_month>}stock),if (dimension='Git',sum({<calmonth=$(v_max_month>}Git),(sum({<calmonth=$(v_max_month>}stock)+sum({<calmonth=$(v_max_month>}git))

i just want to know that that how can i use set analysis insted of if condition.

Please help me out

[whiteline]

It depends on

1. your data-model.

2. dimensions of your chart.

In some cases you just cann't.