Draw tree containing strings as a bar histogram

cbungau · February 3, 2014, 3:17pm

Hello,

I have a tree filled with names of nuclear isotopes, so string variables:

root [1] tree->Scan()

Row * iso *

```
   0 *        B9 *
```
```
   1 *       Be8 *
```
```
   2 *       Be8 *
```
```
   3 *       Be8 *
```
```
   4 *       Be8 *
```
```
   5 *       Be8 *
```
```
   6 *       Be8 *
```
```
   7 *       Be8 *
```
```
   8 *       Be8 *
```
```
   9 *       Be8 *
```
```
  10 *        B9 *
```
```
  11 *       Be8 *
```
```
  12 *        B9 *
```
```
  13 *       Be8 *
```
```
  14 *       Be8 *
```
```
  15 *       Be8 *
```
```
  16 *       Be8 *
```
```
  17 *       Be8 *
```
```
  18 *       Be8 *
```
```
  19 *       Be7 *
```
```
  20 *       Be8 *
```
```
  21 *       Be8 *
```
```
  22 *       Be7 *
```
```
  23 *       Be8 *
```
```
  24 *       Be8 *
```

Type to continue or q to quit ==>

and I would like to draw a histogram with a BAR option, to see how many isotopes and what is the isotopes range I have.

However

tree->Draw(“iso”,“1>0”,“BAR”)

does not produce a bar histogram with all the isotopes names on the X axis.

I would be very grateful if you could please let me know how I could plot this.

Thank you,

Cristian

couet · February 3, 2014, 3:44pm

With option BAR the line border is not drawn. Simply do

tree->SetFillColor(kRed);
tree->Draw("iso","1>0","BAR")

cbungau · February 3, 2014, 3:56pm

Hello,

Thank you very much for your reply. I have tried this, however without success. I have attached the root file and I would be very grateful if you could please try these commands:

tree_Be->Scan() - this will show you the list of isotopes I want to plot
tree_Be->SetFillColor(kRed); - as you suggested
and
tree_Be->Draw(“iso”,“1>0”,“BAR”)

Please let me know any suggestions.

Thank you,

Best regards,

Cristian
isotopes.root (30.7 KB)

couet · February 3, 2014, 4:30pm

What you suggested me to try :

root [0] TFile f("isotopes.root");
root [1] tree_Be->SetFillColor(kRed);
root [2] tree_Be->Draw("iso","1>0","BAR")

gives me the following output:

Which root version are you using ? on which machine ?

cbungau · February 3, 2014, 4:44pm

Thank you for looking into this. I am using root 5.33/03 on Ubuntu 12.04. I have attached my output following those three lines.

Shall I install a newer version of ROOT?

Thank you,

Cristian

couet · February 3, 2014, 4:50pm

try to start root with the option “-l”

root -l

cbungau · February 3, 2014, 4:53pm

Still the same. Shall I upgrade to 5.34.14?

couet · February 3, 2014, 5:00pm

In principal no … do you get something if you remove the option BAR ?

cbungau · February 3, 2014, 5:05pm

It’s exactly the same output. I have upgraded the operating system (kernel, ubuntu libraries, compiler maybe, etc) many times since I installed ROOT, so a new installation might solve this, I don’t know. I am trying a fresh install. If you do have any more ideas, please let me know.

Thank you,

Cristian

ksmith · February 3, 2014, 5:09pm

I can confirm that root 5.32 produces the expected red bar plot.

cbungau · February 3, 2014, 5:19pm

Hello again,

Just finished the installation of 5.34.14 and the plot looks as it should.

I have no idea why my previous installation of 5.33 didn’t work.

Thank you very much for all your suggestions. I didn’t know initially about having to set the fill colour.

Best regards,

Cristian