[Couenne-tickets] [Couenne, a solver for non-convex MINLP problems] #11: support for signed power functions

[Couenne, a solver for non-convex MINLP problems]

#11: support for signed power functions
-------------------------+--------------------------------------------------
 Reporter:  stefan       |       Owner:  somebody
     Type:  enhancement  |      Status:  new     
 Priority:  major        |   Milestone:          
Component:  component1   |     Version:          
 Keywords:               |  
-------------------------+--------------------------------------------------
 Hi,

 attached is a hack for stable/0.3 that allows to deal with so called
 signed power functions of the form {{{abs(x)|x|^n, n >= 1 rational}}}.

 The modifications consists in using the code for odd power functions if
 you have a signed power.

 It seems to give reasonable numbers on the water network design problems
 from D'Ambrosio et.al.

 Things that remain to be done is to check whether the hack also works for
 rational n, I only tried n=2 so far, and to adapt the code in rootQ to
 handle also even integer and rational exponents. For n=1.852, you should
 get q=-0.398399.

 Stefan

-- 
Ticket URL: <https://projects.coin-or.org/Couenne/ticket/11>
Couenne, a solver for non-convex MINLP problems <https://projects.coin-or.org/Couenne>
Couenne, a solver for non-convex MINLP problems