R help - Apr 2013 - Optimization problem

As a simple example, I want to find minimum value for x^2, but it can't be
obtained by:
f<-function(x)x^2
optimize(f,lower=-1,upper=1)

What are other methods to deal with this? I tried DEoptim, still doesn't
work. Any suggustions will be extremely helpful! THanks!


Shelly



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On Apr 10, 2013, at 03:24 , nntx wrote:
> As a simple example, I want to find minimum value for x^2, but it can't
be
> obtained by:
> f<-function(x)x^2
> optimize(f,lower=-1,upper=1)
Works fine for me. What did you expect it to do?
> f<-function(x)x^2
> optimize(f,lower=-1,upper=1)
$minimum
[1] -2.775558e-17

$objective
[1] 7.70372e-34

-pd
> 
> What are other methods to deal with this? I tried DEoptim, still
doesn't
> work. Any suggustions will be extremely helpful! THanks!
> 
> 
> Shelly
> 
> 
> 
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> View this message in context:
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> 
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-- 
Peter Dalgaard, Professor
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com

Thank you professor. I think the minimum value of x^2 between -1 and 1 should
be x=0, y=0. but the result is not that. I am thinking is any wrong with my
thought? 
Thanks for helping me out!



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