Re: setScaleEnable

> Hi John,
> > A while back, I asked about plotting multiple scalars to the same axis
> > and was told that I nust needed to call a SetScaleEnable(true).  Well,
> > I've finally gotten back around to trying this, and I get the error:
> >
> > Single DisplayRealType DisplayYAxis occurs more than once:
> > ShadowType.testIndices
> >
> > What is going wrong?
> This message indicates that more than one RealType is mapped
> to Display.YAxis, and that the display logic is trying to
> apply both at once (e.g., data has MathType (a -> (b, c))
> and both b and c or both a and b are mapped to YAxis).  If
> multiple RealTypes are mapped to YAxis, they cannot be in
> path from root to leaf in the MathType tree (the exact
> defintion is a bit complex, but this is the intuition).
> It is unlikely (but not impossible) that this is caused by the
> ScalarMap.setScaleEnable(true) call.

Right, that's exactly what I want to do.  A while back, I asked about
mapping multiple data sets to the same axis, and got a response saying
that this was possible, if you use setScaleEnable:

> Is it possible to produce plots with more than one axis scale in the
> same direction?  That is, if you have two or more RealTypes mapped to
> the same domain, is it possible to plot them in the same visualization
> space?  If so, how?

Hi John,

As long as you have called GraphicsModeControl's setScaleEnable(true)
you should get an axis scale for every ScalarMap mapping a RealType to
an Axis. e.g.

  display.addMap(new ScalarMap(a, Display.XAxis));
  display.addMap(new ScalarMap(b, Display.XAxis));

should give you a scale for a and b along the x axis, unless I am
missing something.

So, was this advice wrong?  Is it not possible to plot two lines or two
surfaces (or whatever) in the same display?  (For instance, a
"climatogram" plotting temperature and precipitation vs. time.)  This
functionality is important to the educational visualization application
I am working on.

org:SRI International;Center for Technology in Learning
title:Software Engineer
adr;quoted-printable:;;333 Ravenswood=0D=0ABN 261=0D=0A;Menlo Park;CA;94025;USA
fn:John Brecht