Start Period and End Period calculation in Visual Analytics

[makarand]

Hi all I want to create two variables Start_Period and End_Period like shown in below Start_Period= End_Period (prev value for respective project) End_Period = Start_Period + New_Cust - Cust_Left What I have is Month Project New_Cust Cust_Left what I need to do is Start_Period and End_Period Month Project Start_Period New_Cust Cust_Left End_Period periodCalc 11-Apr a 0 131 22 109 0.201835 11-May a 109 70 85 94 0.904255 11-Jun b 94 55 70 79 0.886076 11-Jul a 79 79 63 95 0.663158 11-Aug a 95 154 96 153 0.627451 11-Sep b 153 185 90 248 0.362903 11-Oct aa 248 181 103 326 0.315951 11-Nov a 326 161 114 373 0.30563 11-Dec s 373 231 97 507 0.191321 12-Jan a 507 183 86 604 0.142384 Any help would be highly appreciated. Thanks in advance. Mac

[LinusH]

At least in my mobile your data is nearly unreadable.
Please provide sample have and want data in form of cards/datalines.
What VA constraints do you have (in terms of what kind of use for the resulting data do you see)?