scipy cobyla doesn't converge

scipy cobyla doesn't converge

References

Reference NO 1

http://stackoverflow.com/questions/13654107/scipy-cobyla-doesnt-converge

Reference NO 2

https://github.com/scipy/scipy/blob/master/scipy/optimize/_minimize.py

Reference NO 3

http://dsnra.jpl.nasa.gov/software/Python/python-modules/scipy.optimize.html

Reference NO 4

http://ab-initio.mit.edu/wiki/index.php/NLopt_release_notes

Reference NO 5

http://modular.math.washington.edu/home/wstein/www/home/nborie/sage/local/lib/python2.7/site-packages/scipy/optimize/_minimize.py

Reference NO 6

http://pydoc.net/Python/scikits.statsmodels/0.3.1/scikits.statsmodels.sandbox.tsa.garch/

Reference NO 7

http://europepmc.org/articles/PMC3638882

Reference NO 8

http://code.metager.de/source/history/scipy/scipy/