Looks like you've found a bug; the trendline equations seem to be completely wrong for all polynomial types. I filed a bug report <https://code.google.com/p/google-visualization-api-issues/issues/detail?id=1658> on this; you can "star" the issue to get updates on a fix.
On Thursday, July 3, 2014 3:53:57 PM UTC-4, Gary Hurtz wrote: > > I am adding trendlines to a scatter chart, and while the trendlines > themselves match my data reasonably well, the equations displayed in the > labels are wrong. I am using polynomial trendlines with order = 2. > > I have attached an example. Taking the 'total' trace as an example, the > label indicates y = 0.1x^2 + 3.1, which describes a parabola that is > centered about x=0 and offset in y by 3.135, which clearly does not > describe the trendline that was plotted. The equation should be more like y > = a + b*(x-c)^2. Moreover, the label indicates that the y offset is ~3.1 > while the data indicates it should be more like 1.8. > > Does anyone else see this behavior? > > -gary > -- You received this message because you are subscribed to the Google Groups "Google Visualization API" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/google-visualization-api. For more options, visit https://groups.google.com/d/optout.
