How to create a customized trend line in a chart?

[#1]

Hi, I need to create a customized linear trend line of the graph shown below:

My trend line should start from the value of "gen-mar 2008" (aproximately 0 in this case) and go straight to the value of "lug-set 2013" (aproximately 1,300,000). How can I do that? Thanks.

[Gysbert_Wassenaar]

Add another expression. Something like =if(Month=min(total Month) or Month=max(total Month), sum(Value)). And don't suppress Zero-Values.

[alexandros17]

La cosa più semplice che mi viene in mente è quella di caricare con un load inline una serie di valori da utilizzare poi come espressione:

quaklcosa simile a:

load * inline [

mese, qty

gen-mar 2008, 0

apr-mag 2008, 1000

..... e così via fino al tuo valore

];

fammi sapere

[#4]

It's not my case, the dimension is dynamic as is the range of months.

[#5]

My chart is dynamic, the user can select the period of analysis and through the set analysis i check the dates. If I understood well I should write something like this:

if(Dimension1='gen-mar 2008' or Dimension1='lug-set 2013', sum(Value)).

Is that correct?

[#6]

I solved writing this:

=If(Only({$<DATE={">=$(vDateMin)<=$(vDateMax)"}>} MonthName(DATE))=MonthName('$(vDateMin)')

     OR

    Only({$<DATE={">=$(vDateMin)<=$(vDateMax)"}>} MonthName(DATE))=MonthName('$(vDateMax)') ,

  Sum({$<DATE={">=$(vDateMin)<=$(vDateMax)"}>} VALUE)

)

Where vDateMin and vDateMax are variables edited by the user, and MonthName(DATE) is the calculated dimension of the chart.