Scatter graph and Trend line

[VGrillot]

Hi,

I'm trying the TTrendFunction with a scatter graph.
In this graph there is a compact cloud, and few lost points, most on the right.

Here a screenshot if I add a trend line:




It's obvious that the trend line is false. At least the trend line is not what could be expected.

Is there a tool somewhere in steema library to automatically detect cloud, and ignore losts points ?


Here the result if I remove "manually" losts points, and add a new trend line (in green):



Thanks for any help,
Vincent.

[Yeray]

Hi Vincent,

Yes, it seems that points far of the core are more significant for the function than the others.

As you say, one workaround could be setting a condition to filter the "distant points" but I'm afraid I can't think on a general solution right now. I recommend you, if possible, to do your custom filter knowing the characteristics of your series.

You could create a dummy points series inactive, copy the validated points from the original one to it, and assign the trend function to this filtered series.