Re: NMinimize Bug in Mathematica 7.0?

*To*: mathgroup at smc.vnet.net*Subject*: [mg96248] Re: [mg96197] NMinimize Bug in Mathematica 7.0?*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Tue, 10 Feb 2009 05:50:52 -0500 (EST)*Reply-to*: hanlonr at cox.net

poly = x^4 - 3 x^2 + x; Plot[poly, {x, -2, 2}, PlotRange -> {-3.6, .5}] NMinimize[poly, x] {-1.07023,{x->1.1309}} Use Minimize Minimize[poly, x] // N {-3.51391,{x->-1.30084}} A constraint NMinimize[{poly, x < 0}, x] {-3.51391,{x->-1.30084}} Or a starting interval NMinimize[poly, {x, -2, 1}] {-3.51391,{x->-1.30084}} Bob Hanlon ---- appris at att.net wrote: ============= Here is an example from Mathematica's user's guide: In[8]:= NMinimize[x^4 - 3 x^2 + x, x] Out[8]= {-3.513905039, {x -> -1.300839566}} however, trying to replicate it, I get the following: In[2]:= NMinimize[x^4 - 3 x^2 + x, x] Out[2]= {-1.070230182, {x -> 1.130901122}} One way to find the global min, I had to use a constraint such as x<0. Has anyone come across such a problem? In[3]:= $Version Out[3]= "7.0 for Microsoft Windows (32-bit) (November 10, 2008)" Thanks.