Chart Expression with date functions

[#1]

Hello,

I have a table Shipping with columns ship_id, PartNum, ship_date etc. I am trying to create a chart .

The first dimension is PartNum, second is Month. For each month, I have to calculate this expression => 1/X and display this value in the chart

Where x is the count(ship_id) for ship_date within 12 months but starting from (month - 2).
For example, if month selected is July 2007, then start counting ship_id by going back two months i.e May 2007

For Jul 2007, need count(ship_id) for ship_date between Jun 2006 to May 2007
For Aug 2007, need count(ship_id) for ship_date between Jul 2006 to Jun 2007

How can I construct this expression? Please help.

[#2]

Hi,

please see the attached example. It should give you a hint to solve your problem.

Good luck!

Rainer

[#3]

Hi Rainer,

I was able to open your file the first time, couldn't open it later. Can you please attach the file again?
Also, after posting this question, I tried this.
Created a chart.
The first dimension is PartNum, second dimension is Month(ship_date)
Then defined this expression

if( Month(ship_date) < Month( AddMonths(ship_date, -2) ) OR
Month(ship_date) > Month( Addmonths(ship_date, -14) ), count(ship_id_) )

But not sure, if this is the correct expression.

[#4]

Hi,

here are the application again.

In your expression it seems to me that you have to change "or" in to "and".

Rainer