Rolling cumulative sum by groups of column entries

[#1]

Hi,

I am trying to create the cumulative sum column as shown in the table below. 

When I use the Col cumulative sum( value) directly, it gives cumulative sum for entire value column. Can anyone please help me understand how to calculate the cumulative sum for groups of Type as shown in table below?

Name	Type	value	cumulative sum
AAA	T1	1	1
AAA	T1	10	11
AAA	T1	32	43
AAA	T1	4	47
AAA	T2	2	2
AAA	T2	3	5
AAA	T2	5	10
AAA	T2	6	16
BBB	T1	32	32
BBB	T1	34	66
BBB	T1	5	71
BBB	T1	67	138
BBB	T2	34	34
BBB	T2	32	66
BBB	T2	7	73
BBB	T2	8	81

[#2 · Accepted solution]

Use the by capability within the Col Cumulative Sum() function.

col cumulative sum(:value, :Name, :Type);

[#3]

Thank you for quick and precise answer :)

[#4]

Hi txnelson - I'm trying to do a very similar task, however I'm missing something basic.  

I have a list of projects with columns for date_start, status, description, etc. 

I would like to create a graph demonstrating a cumulative total of "Active" projects, grouped by m/y.  I see this as basically a running count function grouped by date. (starting date format if d/m/y and spans multiple years)

I created the m/y column for grouping, but I haven't been able to graph the count of projects organized by the m/y group. I think I'm missing something basic. 

If there is a scripting solution, I will need a guide as to how to input it as I'm not experienced with JSL.  

Thanks

[#5 · Accepted solution]

Use
Tables=>Summarize
Using your m/y column as the grouping column, and nothing else as the statistics column. The result will give you a data table that can be plotted where # Rows is the count of projects for that m/y

[#6]

Thanks! This worked perfectly.