Trend line showing the combination of data?

[#1]

Hi,

I have two Line charts.

Chart A have

Dimension: Band

Expression: Sum(Number of Cases)

Chart B Have

Dimension: Band

Expression: Sum(Cases)

I want to combine the two charts. I need to show the trend line of sum of Cases when compared to last week and current week.

Can anyone suggest me please how to set this.

Thanks.

[bbi_mba_76]

I set the trendlines only for the difference

[#3]

Thanks. seems found the solution But I will let you know if this is not my user needs?

[its_anandrjs]

Create a single chart

Dimension:- Band

Expression for 15042014:- Sum({< Date = {'$(=date( WeekStart(Today())-6))'}>} [Number of Cases])

Expression for 23042014:- Sum({< Date = {'$(=Today()))'}>} Cases)

Expression Difference:- Sum({< Date = {'$(=date( WeekStart(Today())-6))'}>} [Number of Cases]) -

                                   Sum({< Date = {'$(=Today()))'}>} Cases)