RE: TH2 coz & empty bins

Hi Alessandro,

I see your point too. Yes we can may be make a special case for TProfile2D. I guess the test should be done on the value returned by GetBinEntries .. right ? I do not think there is a need for a new option in a such case, as we are really sure the bin is empty. But we will wait after the release to test that. We cannot introduce new features now. The release is too close.

Cheers, Olivier

-----Original Message-----
From: Alessandro Thea
Sent: Thursday, December 10, 2009 4:59 PM To: Olivier Couet
Cc: roottalk (Mailing list discussing all aspects of the ROOT system.) Subject: Re: [ROOT] TH2 coz & empty bins

Hello Olivier,
thank you for you prompt answer. I see your point. Yet, the TProfile2D knows about the number of entries per bin. Maybe the option to show/hide them in the TProfile2D case should be left to the user.

Cheers,
-a

On Dec 10, 2009, at 4:42 PM, Olivier Couet wrote:

> Hi,
> Yes this is how the COL option is implemented. All details are here:
> http://root.cern.ch/root/html/THistPainter.html#HP14
> We end up to this solution after long discussions with users. It
> appeared it is the most reasonable one. The problem is that when you
> have an histogram with a negative minimum there is no way to know if a
> bin with contain 0 is really an empty which was never filled or if it is
> a bin filled several times and the sum of the weights end up being 0.
> Cheers,
> O.Couet
>
>
> -----Original Message-----
> From: owner-roottalk_at_root.cern.ch [mailto:owner-roottalk_at_root.cern.ch]
> On Behalf Of Alessandro Thea
> Sent: Thursday, December 10, 2009 4:33 PM
> To: roottalk (Mailing list discussing all aspects of the ROOT system.)
> Subject: [ROOT] TH2 coz & empty bins
>
> Hello rooters,
> We are having a problem dealing with a THProfile2D drawn with the "col"
> option.
> I fear this might have been already discussed in the past, forgive me if
> I'm reopening the discussion.
> The TProfile2D we use is filled incrementally and allows both positive
> and negative values. When displayed it is plotted in color ("COL").
> Now, the trouble is the THistPainter paints the empty bins if zmin < 0,
> doesn't paint them if otherwise.
>
> For us is important to distinguish between empty bins and bins which
> value is 0 or close to 0.
> Isn't there a way to force the empty bins to be hidden? I have found it
> for the lego plot ("0" option) but not for the other drawing modes.
>
> Thank you in advance for any help.
> Alessandro
>
> ________________________________________________________________________
> __
>
> ETH Zurich
> Dr. Alessandro Thea
> Institute for Particle Physics
>
> CERN, European Laboratory for Particle Physics,
> CH-1211, Geneve 23, Switzerland,
> PH/UCM, Office 32-2-B03, Mailbox: F17500
>
> Tel: +41-76-487-1800 E-Mail: Alessandro.Thea_at_cern.ch
> ________________________________________________________________________
> __
>

  ETH Zurich
  Dr. Alessandro Thea
  Institute for Particle Physics

  CERN, European Laboratory for Particle Physics,   CH-1211, Geneve 23, Switzerland,
  PH/UCM, Office 32-2-B03, Mailbox: F17500

  Tel: +41-76-487-1800 E-Mail: Alessandro.Thea_at_cern.ch