Minuit.hesse() doesn't compute parameter errors (and there is no warning)

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What steps will reproduce the problem?
1. Run the attached script bb_minuit.py (requires bb_utils.py, which is also 
attached)
2. You can also run bb_scipy.py if you like (also requires bb_utils.py), which 
gives correct results.

The correct errors that hesse() should produce are
bb_utils.BoxBOD.perr = np.array([1.2354515176e+01, 1.0455993237e-01])

The output I get is attached as bb_minuit_output.txt

What version of the product are you using? On what operating system?
pyminuit 1.2.0 linked against SEAL-Minuit 1.7.9 with python 2.7 on Mac OS X 
10.7 Lion

As I already suggested in ticket #30, it would be nice if some unit tests for 
hesse() and minos()
were included in pyminuit.
At the moment I don't know if I am using bad parameters for hesse() or if my 
version of pyminuit is broken.

Original issue reported on code.google.com by [email protected] on 29 Aug 2011 at 11:18

Attachments:

• bb_utils.py
• bb_minuit.py
• bb_scipy.py
• bb_minuit_output.txt