How to create a trend line in cfchart?

I  can create a scatter chart in cfchart - but I do not know how to create  a linear regression trend line in the same chart as a second data  series.

Kodemonki provided an answer in a forum discussion a few years  ago (http://forums.adobe.com/message/192848#192848).

But I am not able to make it work (I have a dangerously small  knowledge of coldfusion and statisitcal formulas).

Can someone tell me  where i put in my to data query variables - such as for a query that  gives results for two data fields, "Item1" and "Item2".

Thanks!

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Here is Kodemonki's solution:

<!--- The min setting is a preference based on how you want the data to be displayed. --->

<!---<cfset min = arrayMin(grabData["value"]) - 5>--->

     <cfset min = 0>

     <cfset max = ceiling(arrayMax(grabData["value"])) + 1>

     <cfset n = grabData.recordCount>

     <cfset sum_x = 0>

     <cfset sum_x2 = 0>

     <cfset sum_xy = 0>

     <cfloop from="1" to="#grabData.RecordCount#" index="i">

          <cfset sum_x = sum_x + i>

          <cfset sum_xy = (i*grabData.value) + sum_xy>

          <cfset sum_x2 = sum_x2 + (i*i)>

     </cfloop>

     <cfset sum_y = arraySum(grabData["value"])>

     <cfset slope = round(((n*sum_xy) - (sum_x*sum_y))/((n*sum_x2) - (sum_x*sum_x)))>

     <cfset intercept = round((sum_y - (slope*sum_x))/n)>

     <cfset best_fit = QueryNew("id, value")>

     <cfloop from="1" to="#grabdata.RecordCount#" index="i">

          <cfset queryAddRow(best_fit)>

          <cfset value = round((slope*i) + intercept)>

          <cfset QuerySetCell(best_fit, "id", grabData.xlabel)>

          <cfset QuerySetCell(best_fit, "value", value)>

     </cfloop>

     <cfchart  scalefrom="#min#" scaleto="#max#" title="#GrabDatapointInfo.label#"  format="jpg" chartHeight="450" chartwidth="500"  xaxistitle="Month/Year">

          <cfchartseries type="line" query="best_fit" valuecolumn="value" itemcolumn="id"/>

          <cfchartseries type="line" query="grabData" valuecolumn="value" itemcolumn="xlabel"/>

     </cfchart>