About the TF1

From: <yczhang_at_ihep.ac.cn>
Date: Mon, 4 Oct 2010 20:28:50 +0800

Hi rooters,

   I've met a strange problem:
   I wrote a function called changedfitf to do PMT calibration. When I set the TH1F's range from 0 to 300 and then use:    TF1 *myfunc = new TF1("myfunc",changedfitf,0,300,9);    It can work very well:

------------------------Changed Pmt Full Model Fit-------------------------

The zero bin num is 10 the max non zero bin is 198 the max_content_bin_X=44.5
xlow=0 larger than 3sigma(3.85062) of Q0(0) the corrected mu=0.133396(the raw mu=0.133396) the data mu = 0.133396
the p.e. maximum for fitting is : 6
the fitting range is:(0, 197)
mu = 0.133396
Q0 = 0
Delta0 = 3.85062
Q1 = 45.0928
Delta1 = 13.5278
w = 0.02
A = 0.015

Threshold = 6.01237
Thresigma = 1.33608


===============================Fitting==========================

=================================TF1==========================

 FCN=168.433 FROM MIGRAD    STATUS=CONVERGED    1313 CALLS        1314 TOTAL
                     EDM=3.6852e-11    STRATEGY= 1  ERROR MATRIX UNCERTAINTY   2.3 per cent
  EXT PARAMETER                                   STEP         FIRST   
  NO.   NAME      VALUE            ERROR          SIZE      DERIVATIVE 
   1  #mu          1.09114e-01   2.87723e-03  -6.40448e-08  -6.05769e-03
   2  Q_{0}        0.00000e+00     fixed    
   3  #sigma_{0}   3.85062e+00     fixed    
   4  Q_{1}        4.50307e+01   1.80311e-01   2.74274e-06  -1.42659e-04
   5  #sigma_{1}   1.34602e+01   3.09561e-02   7.94038e-05** at limit **
   6  W            7.63768e-02   5.74221e-03  -5.65470e-07  -6.53761e-05
   7  #alpha       9.43000e-02   6.93699e-03   6.21250e-08   6.44549e-04
   8  Thre         1.43637e+01   2.69871e-01  -1.03166e-06  -2.27925e-05

   9 #sigma_{Thre} 3.03582e+00 1.31803e-01 -6.48437e-07 5.15239e-05

---------------------------------Completed!---------------------------------

   But when I set the TH1F's range from 0 to 1000 and then use:    TF1 *myfunc = new TF1("myfunc",changedfitf,0,1000,9);    It will not work:
===============================Fitting==========================
=================================TF1==========================
*** glibc detected *** malloc(): memory corruption: 0x097bce60 *** It will break when reaching "TF1 *myfunc = new TF1("myfunc",changedfitf,0,1000,9)" I was very confused with this problem
Can anyone help me? Thanks a lot!

--
Best regards,
ZhangYiChun
Institute of High Energy Physics
Yuquan street 19， Shijingshan district, Beijing, China 
EMail: yczhang_at_ihep.ac.cn

Received on Mon Oct 04 2010 - 14:29:05 CEST