title: Running Value Chart in SSRS - How to get each series to start at 0?
body: <p><img src="https://i.stack.imgur.com/wjJTN.png" alt="enter image description here"><img src="https://i.stack.imgur.com/b459U.png" alt="enter image description here"></p>
  
  <p>I have a table in SSRS, with income from two campaigns.</p>
  
  <p>My columns are:</p>
  
  <ul>
  <li>serialnumber</li>
  <li>DateOfPayment</li>
  <li>PaymentAmount</li>
  <li>DaysSinceCampaign</li>
  <li>Campaign</li>
  </ul>
  
  <p>I want my chart to plot a running total of paymentamount by DaysSinceCampaign for each campaign (bs13 and bs12). I'm pretty close, as shown above - but for some reason, the BS13 campaign starts at 20,000, appearing to be adding on to BS12 - when it is supposed to start at 0.</p>
  
  <p>In the Values section for Chart Data, I have used this formula: </p>
  
  <pre><code>=RunningValue(Fields!PAYMENTAMOUNT.Value,SUM,nothing)
  </code></pre>
  
  <p>I have tried changing 'nothing' to "campaign", and have tried defining 'Campaign' as a row group and a column group - but it keeps returning the same error: that the scope parameter must be set to a string constant equal to a containing group.</p>