I have a TH1F histogram, which is divided in another TH1F one (efficiency). I have the Y axis with units from 0 to 1 in jumps of 0.2. I want to make it to be an axis of 0 - 100 in jumps of 20. It’s efficiency and I want it in %. How can I do that?
I try to use the TGaxis, so I defined a new axis, and after a long time I even got it set to place and just in the correct size, but how can I take the other axis off (I mean the original Y axis of the histogram)?
[quote=“Aye”]I have a TH1F histogram, which is divided in another TH1F one (efficiency). I have the Y axis with units from 0 to 1 in jumps of 0.2. I want to make it to be an axis of 0 - 100 in jumps of 20. It’s efficiency and I want it in %. How can I do that?[/quote]What about to mulitply it by 100:
See: root.cern.ch/root/htmldoc/src/TH1.cxx.html#6h37J :
void TH1::Divide(const TH1 *h1, const TH1 *h2, Double_t c1, Double_t c2, Option_t *option)
{
// -*-*-*Replace contents of this histogram by the division of h1 by h2*-*-*
// ==============================================================
//
// this = c1*h1/(c2*h2)
//
To turn off an axis you can do:
hpx->GetYaxis()->SetLabelSize(0);
hpx->GetYaxis()->SetTickLength(0);[quote]What about to mulitply it by 100:
See: root.cern.ch/root/htmldoc/src/TH1.cxx.html#6h37J :
void TH1::Divide(const TH1 *h1, const TH1 *h2, Double_t c1, Double_t c2, Option_t *option)
{
// -*-*-*Replace contents of this histogram by the division of h1 by h2*-*-*
// ==============================================================
//
// this = c1*h1/(c2*h2)
//
[/quote]
When I just try to multiply I get this kind of error:
error: invalid operands of types double' andTH1F*’ to binary `operator*’
If I try for the divid with c1 (see code here) I get:
Double_t number = 0.01;
Eta_dist->Divide( Ref_Eta_dist, number );
error: no matching function for call to `TH1F::Divide(TH1F*&, Double_t&)’
/afs/cern.ch/sw/lcg/external/root/5.12.00/slc4_ia32_gcc345/root/include/TH1.h:152: note: candidates are: virtual void TH1::Divide(TF1*, Double_t)
/afs/cern.ch/sw/lcg/external/root/5.12.00/slc4_ia32_gcc345/root/include/TH1.h:153: note: virtual void TH1::Divide(const TH1*)
/afs/cern.ch/sw/lcg/external/root/5.12.00/slc4_ia32_gcc345/root/include/TH1.h:154: note: virtual void TH1::Divide(const TH1*, const TH1*, Double_t, Double_t, const Option_t*)
But I did managed to take the other axis off.
I have one more question about adding an axis. Is there a better way to put an axis in the Y-axis possition then guessing (and trying) its (xmin, ymin) and the same for (xmax, ymax) ?
TGaxis have no getters for the axis position because the axis position should be specified at creation time so they are known by the program creating TGaxis… May be I missunderstood this question.
It’s ok, I managed to take the Y-(original-)axis off, and now it’s perfect.
Thank you very much for your help!