JSROOT Draw TMultiGraph with opt "SAME" cannot update ymax

ROOT
1

I am using JSROOT to provide a web-display of online test-data.

When upgrading to JSROOT version from 4.8.2 to above 5.00
only the first TMultiGraph is shown, but not the ones drawn with
opt “SAME” containing points with x-values beyond the first graph.
In Vs.482 it was sufficient to update main_painter().xmax
before calling RedrawPad(), but since Vs.500 this does not work anymore.

It works also in Vs.500+ if I plot the TGraphs instead of the TMultiGraphs,
but I need the TMultiGraphs.

A workaround would be to loop over all TGraphs to create a new TGraph
concatenating all points and then collect them in a single TMultiGraph
and draw only this one, but maybe there is a better solution ?

A short standalone example is available here - only difference is JSROOT-Vs:
http://accms04.physik.rwth-aachen.de/~amslab/JSROOT_TEST
The point at x=9.05 is from the 2nd TMultiGraph.

I hope someone can help,
many thanks in advance,
Thorsten Siedenburg

JSROOT Version: 5.0.0+
Platform: Firefox 58
Compiler: Not Provided

2

Hi Thorsten,

Why you try to use several TMultiGraph objects?
Can you put all graphs into one TMultiGraph?

As a workaround, you can create histogram for the first multigraph object and configure all limits yourself:

   mg1.fHistogram = JSROOT.CreateTH1(100);
   mg1.fHistogram.fXaxis.fXmax = Xmax;
   mg1.fHistogram.fMinimum = 0;
   mg1.fHistogram.fMaximum = 10;

Full example: http://jsroot.gsi.de/files/tmp/mgtest.htm

This should work for both JSROOT versions.
But again - recommended way is to use single TMultiGraph.

Regards,
Sergey

3

Hi Sergey,

thanks a lot for your quick answer.

So my “workaround” is the recommended way.

I used several TMultiGraphs, because data is available
in daily files containing TGraphs.

Since drawing all daily TMultiGraphs with opt “SAME” worked
I was too lazy to first merge all points into single TGraphs.

Will do this now.

Thanks again

Thorsten