-Original Message-
From: Mike Lawrence [mailto:[EMAIL PROTECTED]
Sent: Monday, October 01, 2007 10:27 AM
To: Ravi Varadhan
Cc: 'Rhelp'
Subject: Re: [R] optimize() stuck in local plateau ?
I may be misunderstanding, but my example seems to v
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-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mike Lawrence
Sent: Monday, October 01, 2007 1:29 AM
To: Rhelp
Subject: [R] optimize() stuck in local plateau ?
Hi all,
Consider the
Given a univariate problem where the maximum
must be between -1 and 1, I would test with a grid
of points, then refine that if necessary.
Patrick Burns
[EMAIL PROTECTED]
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")
Mike Lawrence wrote:
>
Hi Mike,
You function is discontinuous at -0.8, so you can
expect everything :-}! But this is not the only
problem. The algorithm for optimize never gets there.
In general there exists no universal method to find
the global maximum of a function (unless it satisfies
certain conditions). You can al
Hi all,
Consider the following function:
my.func = function(x){
y=ifelse(x>-.5,0,ifelse(x< -.8,abs(x)/2,abs(x)))
print(c(x,y)) #print what was tested and what the result is
return(y)
}
curve(my.func,from=-1,1)
When I attempt to find the maximum of this function,
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