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Re: problem with LessEqual::nord:

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  • Subject: [mg115851] Re: problem with LessEqual::nord:
  • From: Daniel Lichtblau <danl at>
  • Date: Sat, 22 Jan 2011 03:25:04 -0500 (EST)

tarun dutta wrote:
> I am using "NMINIMIZE" to get the result of a function which contains
> complex term.after executing the program it is showing the following
> error--
> LessEqual::nord: Invalid comparison with 155.698+0. I attempted. >>
> can you explain the reason and how will I be free from this kind of
> error?
> thanks in advance.
> regards,
> tarun

It looks like a "phantom" imaginary part that is caused by cancellation 
of imaginary parts in sums of approximate complex numbers. If so, and if 
you know in general that all things you evaluate end up being real (up 
to truncation error) you might get rid of it by wrapping the function 
being evaluated in Re[].

Daniel Lichtblau
Wolfram Research

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