Variable to set lookback period on charts

[tinkerz1]

Hi,

Is there any way to use a variable to set the number of data items to load, working back from the latest date.

For instance, if there are 12 dates on the x axis and I want the last 6 only how would I do it.

x - axis

1/06  1/07  1/08  1/09  1/10  1/11 1/12

Then use the same approach but use a variable to set 9 months?

1/12/2010

1/11/2010

1/10/2010

1/09/2010

1/08/2010

1/07/2010

1/06/2010

1/05/2010

1/04/2010

1/03/2010

1/02/2010

1/01/2010

[Anonymous]

you can either do it in Dimension or in Expression (then you Need to do it for all expressions!)

Dimension:

if (yourdatefield>=mindate and yourdatefield<=maxdate, yourdatefield)

mindate could be addmonths(max(yourdatefield),-6) and maxdate could be max(yourdatefield)

i would use variables to hold the Dates

expression

sum({<yourdatefield={'>=$(=mindate)<=$(=maxdate)'}>}Amount)

[tinkerz1]

I have written this in my dimension

=Date(if(Num#(Dates)>=Min_Date and Num#(Dates)<=Max_Date,Num#(Dates)),'DD/MM/YY')

And my variables are

Min_Date

addmonths(max(num#(Dates)),-6)

Max_Date

max(num#(Dates))

The dates across the bottom are correct, but I get an extra column showing the total.

It must be adding all the cells up that are inside the range, how do i get around this?

[tinkerz1]

Also I can't change the variable expression Min_date

=addmonths(max(num#(Dates)),-6)

Every time I try and change the 6 to a 3, I press OK but the 6 wont change

Any Ideas?

[tinkerz1]

  This now works for the window, if I change [Lookback period for dates], the window changes.

But I still get the total column on the end.

=addmonths(max(num#(Dates)),-([Lookback period for dates]))

=date(max(num#(Dates)))

[tinkerz1]

The total at the end is the total of all date outside the date range.

How is this working to create this?

[tinkerz1]

In Dimensions 'surpress when value is null'

It looks like that total data was the 'FALSE' side of the equation that was plotting.