primary axis fitting

[tristan.maillet]

I have a line chart, with two series on it.

When i use a primary and a secondary axis, by double clicking on one
serie, then on axis label, choosing Plot series in : "Secondary Axis",
my chart looks like :

(maybe it won't display, you have two lines and two axis, and the two
lines have not the same value at all)


But now, if i choose (for the FF serie) "Primary Axis", i get :

(the two lines/series are now very close, expected a few points. Only
the FF serie has changed, the other one remained unchanged)

You can see that the data has been fitted to be near the ED serie, so
the left axis does not correspond to the actual values of FF serie.
Excel must have applied a transformation to the initial data...
My question is : what is the transformation of data that have been used
by Excel to "fit" the other serie ? I just checked that it is not a
linear rescalling, so i really don't know what Excel did compute to
have such a good fitting of data (actually I want to use the FF serie
to predict the ED one, so it could be of very great help to find the
answer...).

Many many thanks for your help !

 

[Jon Peltier]

The two charts do not use the same FF data. Are you sure that there aren't
three series of data, where one chart uses A and B and the other uses A and
C? Excel doesn't just apply transformations to data like this.

- Jon