RE: [ROOT] Strange ntupe behavior.

From: Philippe Canal (pcanal@fnal.gov)
Date: Thu Sep 05 2002 - 23:59:06 MEST 

Hi Ed,

The problem appears only on Windows because of their choice for the result
of operator> and operator< when applied to numerical NaN.  Your file indeed
has some Nan:

root [7] nt->Scan("yd","yd<-30")
************************
*    Row   *        yd *
************************
*    28482 *   -1.#IND *
*    28490 *   -1.#IND *
*    28520 *   -1.#IND *
*    28534 *   -1.#IND *
*    28540 *   -1.#IND *
*    28541 *   -1.#IND *
*    28589 *   -1.#IND *
*    28622 *   -1.#IND *
*    28631 *   -1.#IND *
*    28640 *   -1.#IND *
*    28681 *   -1.#IND *
*    28700 *   -1.#IND *
*    28730 *   -1.#IND *
*    28733 *   -1.#IND *
************************

Somehow this is not a problem on Linux where comparaison to Nan are always
false. While it is a problem on Windows where the comparaison are sometimes
true, sometimes false.  Hence on Linux the Nan always appear as underflow or
overflow, while on Windows they are being used to try to determine the range
of the histogram.

Cheers,
Philippe.

-----Original Message-----
From: owner-roottalk@pcroot.cern.ch
[mailto:owner-roottalk@pcroot.cern.ch]On Behalf Of Ed Oltman
Sent: Thursday, September 05, 2002 1:58 PM
To: Roottalk@Pcroot. Cern. Ch
Subject: [ROOT] Strange ntupe behavior.


Hello,
 I have a root file with a single ntuple created with:

    TFile *f = new TFile("test.root","RECREATE");
    TNtuple *nt = new TNtuple("nt","ff","x:y:z:xd:yd:zd:s");
                 .
                 .
    for(int i=0;i<totInShell;i++)
    {
                 .
                 .
        nt->Fill((x,y,z,xd,yd,zd,s);
    }
    f->Write();
    f->Close();

I would be happy to send the root file - its 339 kBytes.   The file is
generated with a standalone application (Win2K + VC6.0)

I then open the ntuple in a normal root session:

    TFile *f = new TFile("test.root")

At the bottom of this not is result of nt->Print()

Here's the problem:  I can display any single branch with nt->Draw() EXCEPT
xd and yd.  IF I try these, root consumes all my cpu until I type ctrl-C.
However, I can do

    nt->Draw("xd:x") or nt->Draw("yd:xd") etc...

The only failures I have are nt->Draw("xd") and nt->Draw("yd").  Same
failure occurs if I use a TBrowser object to inspect the ntuple.

Note: I can create a 1D histogram and project xd onto it

    TH1F *pxd = new TH1F("pxd","xd",100,-25.,25.)
    nt->Project("pxd","xd");
    pxd->Draw()

and it works fine.  I have the problem in both 3.02/7 and 3.03/8.
(stand-alone application linked with same version as root.exe)

Any ideas what might be wrong?

Thanks,
Ed Oltman


here is nt->Print()

****************************************************************************
**
*Tree    :nt        : ff
*
*Entries :    30664 : Total =          748011 bytes  File  Size =     331425
*
*        :          : Tree compression factor =   2.63
*
****************************************************************************
**
*Br    0 :x         :
*
*Entries :    30664 : Total  Size=      95994 bytes  File Size  =      40248
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   2.39
*
*...........................................................................
.*
*Br    1 :y         :
*
*Entries :    30664 : Total  Size=      95994 bytes  File Size  =      41533
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   2.31
*
*...........................................................................
.*
*Br    2 :z         :
*
*Entries :    30664 : Total  Size=      95994 bytes  File Size  =      31161
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   3.08
*
*...........................................................................
.*
*Br    3 :xd        :
*
*Entries :    30664 : Total  Size=      95997 bytes  File Size  =      55843
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   1.72
*
*...........................................................................
.*
*Br    4 :yd        :
*
*Entries :    30664 : Total  Size=      95997 bytes  File Size  =      55933
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   1.72
*
*...........................................................................
.*
*Br    5 :zd        :
*
*Entries :    30664 : Total  Size=      95997 bytes  File Size  =      30069
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression=   3.19
*
*...........................................................................
.*
*Br    6 :s         :
*
*Entries :    30664 : Total  Size=      95994 bytes  File Size  =        594
*
*Baskets :        3 : Basket Size=      32000 bytes  Compression= 161.61
*

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