Does TTree::Draw() support 2-dim arrays?

From: R. Holzmann (phone: 0049/6159/71-2645) (holzmann@axp101.gsi.de)
Date: Fri Sep 25 1998 - 11:57:19 MEST


Dear ROOTers,


does TTree::Draw() support arrays of more than 1 dimension?
Also, what is the notation used to specify index ranges?


My problem is the following:

I have a tree generated with h2root from a PAW CWN tuple.
Here's the output of the PAW n/print command:

PAW> n/print 3011

 ******************************************************************
 * Ntuple ID = 3011   Entries = 10        MDC11
 ******************************************************************
 * Var numb * Type * Packing *    Range     *  Block   *  Name    *
 ******************************************************************
 *      1   * U*4  *         *              * IEVT     * IDEVT
 *      1   * I*4  *         * [0,100]      * S1D1     * NHIT
 *      2   * U*4  *    13   * [0,8000]     * S1D1     * MDCTRK(NHIT)
 *      3   * R*4  *         *              * S1D1     * MDCX(6,NHIT)
 *      4   * R*4  *         *              * S1D1     * MDCY(6,NHIT)
 *      5   * R*4  *         *              * S1D1     * MDCTHETA(6,NHIT)
 *      6   * R*4  *         *              * S1D1     * MDCPHI(6,NHIT)
 *      7   * R*4  *         *              * S1D1     * MDCTOF(6,NHIT)
 ******************************************************************
 *  Block   *  Entries  * Unpacked * Packed *   Packing Factor    *
 ******************************************************************
 * IEVT     *  10       * 4        * 4      *       1.000         *
 * S1D1     *  10       * 12404    * Var.   *    Variable         *
 * Total    *    ---    * 12408    * Var.   *    Variable         *
 ******************************************************************
 * Blocks = 2            Variables = 8       Max. Columns = 3102  *
 ******************************************************************



and the corresponding h3011->Print() output is:

root [10] h3011->Print()
******************************************************************************
*Tree    :h3011     : MDC11                                                  *
*Entries :       10 : Total  Size =     25608 bytes  File  Size =      25608 *
*        :          : Tree compression factor =   1.00                       *
******************************************************************************
*Branch  :Idevt     : Idevt/i                                                *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Nhit      : Nhit/I                                                 *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdctrk    : Mdctrk[Nhit]/i                                         *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdcx      : Mdcx[Nhit][6]/F                                        *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdcy      : Mdcy[Nhit][6]/F                                        *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdctheta  : Mdctheta[Nhit][6]/F                                    *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdcphi    : Mdcphi[Nhit][6]/F                                      *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*
*Branch  :Mdctof    : Mdctof[Nhit][6]/F                                      *
*Entries :       10 : Total  Size =         0 bytes  File Size  =          0 *
*Baskets :        0 : Basket Size =      8000 bytes  Compression=   1.00     *
*............................................................................*



Now, in PAW I could do nice things on the 2dim arrays, like

PAW> n/plo 3011.mdcx(1,2)

and

PAW> n/plo 3011.mdcx(1,1:nhit)

or even select subranges

PAW> n/plo 3011.mdcx(1:3,nhit-10:nhit)

i.e. I had full control over BOTH indices!


How much of this can I do with the TTree::Draw() member function? 



Thanks a lot for any help.

Romain Holzmann




p.s. Tom Moog from ANL posted a similar question quite some time ago, but no
answer has apparently been threaded.



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