TTree::Draw() with expression and dynamic array problem

stefan kluth (skluth@mh1.lbl.gov)
Wed, 19 Aug 1998 10:53:29 -0700 (PDT)


Hi,

I have a tree with dynamic arrays of floats as branches and a basic float
branch. I would like to plot a simple expression involving a dynamic
array, but it doesn't work. Here is an example root session:

*******************************************
* *
* W E L C O M E to R O O T *
* *
* Version 2.00/10 30 July 1998 *
* *
* You are welcome to visit our Web site *
* http://root.cern.ch *
* *
*******************************************

CINT/ROOT C/C++ Interpreter version 5.13.66, July 24 1998
Type ? for help. Commands must be C++ statements.
Enclose multiple statements between { }.
root [0] TFile f1("framework.root");
root [1] ntp1->Print();
******************************************************************************
*Tree :ntp1 : yflips
*
*Entries : 100 : Total Size = 44566 bytes File Size =
44566 *
* : : Tree compression factor = 1.00
*
******************************************************************************
*Branch :ievent : ievent/I
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :sume : sume/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :njets : njets/I
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :JE0yf : JE0yf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :Pyf : Pyf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :P0yf : P0yf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :Eyf : Eyf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :Dyf : Dyf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :Gyf : Gyf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :Lyf : Lyf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
*Branch :E0yf : E0yf[njets]/F
*
*Entries : 100 : Total Size = 0 bytes File Size =
0 *
*Baskets : 0 : Basket Size = 8000 bytes Compression= 1.00
*
*............................................................................*
root [2] ntp1->Draw("njets/sume");
Warning in <MakeDefCanvas>: creating a default canvas with name c1
root [3] ntp1->Draw("Lyf[1]/sume");

Error: No symbol ntp1->Draw("Lyf[1]/sume") in current scope
FILE:/tmp/faaaazuca LINE:1
*** Interpreter error recovered ***
root [5] ntp1->Draw("njets/sume");
Error: No symbol ntp1->Draw("njets/sume") in current scope
FILE:/tmp/gaaaazuca LINE:1
*** Interpreter error recovered ***

The first command "ntp1->Draw("njets/sume");" works as expected. The
second command "ntp1->Draw("Lyf[1]/sume");" cocks up the interpreter, such
that even the first command does not work anymore.

Any ideas? cheers, Stefan

---Stefan Kluth---------------Lynen Fellow----------------|\--|\-------
- LBNL, MS 50A 2160 - phone: +1 510 495 2376 - |/ |/ -
- 1 Cyclotron Rd. - fax: +1 510 495 2957 - |\/\|\/\|' -
---Berkeley, CA94720, USA-----e-mail: SKluth@lbl.gov------|/\/|/\/|----