Equal pad size in TCanvas with one common axis

[smurphy]

Hi,
I would like to have four graphs touching each other in 4 pads (so canvas->Divide(4,1,0,0) ). Problem is I would like them to have all equal size. But if you want to set the title on the one on the right you have to do pad1->SetLeftMargin(.2) to get the title in. But then the frame in this particular pad one becomes smaller. Also the frame line on the far left (pad number 4) is hidden. I would have expected something like setting the border on the whole canvas before dividing but seems I cannot do that.
I attach two screenshots to illustrate better the problem.
Also I would like to have one common title for the x-axes instead of 4 identical.
Any ideas on how to solve those issues?
Thanks very much,
Sebastien Murphy

[Wile_E_Coyote]

Dividing a TCanvas such that the plots are the same size

I would like to divide a TCanvas so that I can have multiple plots with no margins between them, as in this example (root.cern.ch/root/html/tutorials … nes.C.html). When you use TCanvas::Divide it divides the canvas into pads and then each plot is drawn in one of these pads. This is problematic because the bottom row and left column need to contain the axes labels and titles so they end up with smaller areas for actual plotting. With a number of divisions this can be an extremely noticeable and …

TCanvas::Divide leaves unfilled margin

A brutal fix … canvas->Divide(2, 2, 1E-11, 1E-11); // BOTH, “xmargin” and “ymargin”, MUST BE > 0 (I assume Olivier will comment on this issue in a more detailed way -> especially, why pads are not equal in size when any one of “[x|y]margin” is 0. Actually, each pad has a different size in these cases. I can understand that there’s some free space on top for the canvas’es title, but what’s the purpose of the free space on the right side?)

[smurphy]

ok thanks. After a bit of playing around the function provided in $ROOTSYS/tutorials/graphics/canvas2.C worked. Anybody has ideas on how to set only one x-title centred at the bottom?

[couet]

set all the X titles to blank except the central one.

[smurphy]

thanks yes this would be an obvious solution if you had 5 graphs but I have 4 (see previous pictures)

[couet]

you can do some approximative approach by setting only le 2nd pad title and align it to the right…
or a precise one by setting all the titles to blank and draw a centered TLatex yourself.

[smurphy]

ok thanks almost there I think. In the end like you suggested I simply set the beginning of the title for number 2 and the end for number 3 (not the most elegant but ok). TLatex was not printing anything.
Last question how do you flush the x-title of number 3 to the left to make it look appear as one? Can’t find something like axis->SetTitleXPosition(0).
Thanks,
Sebastien

[couet]

Axis title are either in the middle of the axis or at the end… not on the left … sorry …

[smurphy]

ok too bad…

[srishino]

Hi everyone,

I am trying to make six pads with six histograms in them and want one common axis and common label. I could make three together and want three more just below them, but as I am dividing the canvas or pad, its not working at all. Please guide me about how to do it…
I am attaching my code and a screenshot of what i have made.
Thanks a lot…dataplotoneDD2.C (8.6 KB) unnamed2.pdf (17.3 KB) .

[couet]

I cannot run your macro. You did not post the data files.

[srishino]

Hi,

My datafiles are not getting uploaded due to large size. I have made a tarfile and tried it via just paste it website, hope it works.
Please find my data files from the link- https://justpaste.it/3hvgd, https://justpaste.it/edit/29731517/25f5f92a3ae30495

Thank you.

[couet]

@srishino

hope it works

no… this wen site does not allow to download

[srishino]

how should I attach my data files ?

[couet]

May be you can just make a fake macro without data (empty histograms) showing what you want to do.

[srishino]

Hi,
I have attached the files with very less data and code again.
It is giving me three pads and I want total six, three more just below each of them.
Please find the tar file with the code and data files.

Thank you.

datafiles.tar.gz (9.0 KB)

[couet]

Okay, I see now. If you do not want to use Divide you can try to copy what is done in this example.

[srishino]

Isn’t there a simpler code to make 6 pads, the way I made 3 in my code ?
This example seems a bit difficult to understand…

[couet]

In that example just do:

 const Int_t Nx = 3;
 const Int_t Ny = 2;

[srishino]

yes, its working, how do I enter the data of my histograms in each of the six pads ?
I have to make three different histograms in each pad and edit each pad by adding different text to it…

I have added the histograms to this code, where should I draw them to see on the respective pads ?multipad.C (10.4 KB)