Access previous row with mRender

lukasmeyeruk

Dear all,

I have a table of projects with assigned costs. I would like to add a calculated column that shows a cumulative view (i.e. Cost1 + Cost2 + Cost3, etc.). For this, I need to access the value of a given column of the previous row and add it to the value of the current row. I want this to be calculated on the fly so when the sorting changes, the column gets recalculated.

Do you have any idea how I could do this? I tried with fnGetPosition but without any luck. Please find below an short example of my table:

http://live.datatables.net/virudeca/2/

Thanks in advance and best regards,

Lukas