2-axis problem with horizontal crossing

[BorisS]

I have a 2-axis bar/line chart, and the bar values (primary) go from 0 to
18,000, while the secondary goes -4% to 15%. I am having trouble forcing the
axes to both cross at a horizontal 0 (which implies that the primary axis
would have to either start negative and cross at 0 (not preferred, because
logically won't make sense to have a negative number possible for this
access) or have the primary start at 0 and go up, while the secondary starts
at negative (below where the primary is starting to be drawn) and then hits
at zero.

cannot figure out any way to do this. Any help?

 

[Jon Peltier]

This is one of the issues that has led data viz expert Stephen Few to swear
off dual axis charts in "Dual-Scaled Axes in Graphs-Are They Ever the Best
Solution?"
(http://www.perceptualedge.com/articles/visual_business_intelligence/dual-scaled_axes.pdf).

You are better off with two separate charts, one for each of the disparate
data sets. Or you could make a panel chart which shows each data set in its
own panel of a single chart:

http://peltiertech.com/Excel/ChartsHowTo/PanelUnevenScales.html

If you still insist on saddling a single chart with two incompatible scales,
you could try this technique to coerce the two scales into a precarious
balance:

http://peltiertech.com/Excel/Charts/AlignXon2Ys.html

- Jon