Re: Points sampled by FindMinimum

*To*: mathgroup at smc.vnet.net*Subject*: [mg71145] Re: Points sampled by FindMinimum*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Thu, 9 Nov 2006 03:38:16 -0500 (EST)

On 11/8/06 at 6:06 AM, andrew.j.moylan at gmail.com (Andrew Moylan) wrote: >Please consider the following code, which asks FindMinimum to >minimise a simple parabolic function while tracking at which which >points FindMinimum evaluates the function: >func[x_?NumericQ] := (Print[x]; 1 + (x - 1)^2) FindMinimum[func[x], >{x, 0.1}] >The output is: >0.1 0.1 0.1 0.6 0.6 0.6 1. 1. 1. 1. 1. 1. >But I would have expected output more like: >0.1 0.6 1. 1. >Can anyone explain why FindMinimum evaluates func three times at >each test point, instead of once? I rather doubt FindMinimum is evaluating the function three times at each point. I am reasonably certain the difference between sampled points is simply fairly small and the Print statement doesn't show enough digits to make it apparent there is a difference. That is In[4]:= .1000001 Out[4]= 0.1 In[5]:= .1000002 Out[5]= 0.1 -- To reply via email subtract one hundred and four