weird NMaximize behaviour

*To*: mathgroup at smc.vnet.net*Subject*: [mg92049] weird NMaximize behaviour*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Thu, 18 Sep 2008 06:15:53 -0400 (EDT)

I have just encountered strange behaviour by NMaximize (which has been ruining a demonstration I have been working on): This is fine: NMaximize[{(x - 1)^2, -2 <= x <= 2}, {x}] {9., {x -> -2.}} but this definitely is not: NMaximize[{(x - 1)^2, -2 <= x <= 2 && -1 <= y <= 1}, {x, y}] {1., {x -> 2., y -> 0.87904}} The objective function s independent of y, yet NMaximize seems to go off on some wild goose chase and ends up with a very poor "maximum". This does not happen here: NMaximize[{(x - 2)^2, -2 <= x <= 2}, {x}] {16., {x -> -2.}} NMaximize[{(x - 2)^2, -2 <= x <= 2 && -1 <= y <= 1}, {x, y}] {16., {x -> -2., y -> -0.980305}} Kind of weird. Andrzej Kozlowski