Re: help with slow minimize
- To: mathgroup at smc.vnet.net
- Subject: [mg94819] Re: [mg94811] help with slow minimize
- From: DrMajorBob <btreat1 at austin.rr.com>
- Date: Sat, 27 Dec 2008 07:02:51 -0500 (EST)
- References: <200812261042.FAA16381@smc.vnet.net>
- Reply-to: drmajorbob at longhorns.com
You're hoping to choose ONE real variable to minimize a function of SEVEN
real variables??
And that means optimal t would work for ALL possible v1x, v1y, v2x, v1y,
d1, and d2?
Or Minimize should return a breakdown of all possible forms for the
answer, with a t-value paired with different ranges of the other six
variables in every case?
Good luck with that!
Bobby
On Fri, 26 Dec 2008 04:42:29 -0600, olanilsson <per.ola.nilsson at gmail.com>
wrote:
> Hi all,
>
> I am new to mathematica so bear with me.
>
> I have a relatively simple minimization problem:
>
> v1 = {v1x, v1y}
> v2 = {v2x, v2y}
> f[t_] := (1 - t)*v1 + t*v2
>
> Minimize[{Sqrt[f[t].f[t]] + (1 - t)*d1 + t*d2, {t >= 0, t <= 1}},
> t] // FullSimplify // Timing
>
> I have not yet been able to solve this on neither my Mac G5 nor my new
> MacBook (both with 2GB RAM). Mathematica runs out of memory after
> about two days.
>
> I assume I do something wrong? Can someone please give me a hint or
> explain why this problem is so difficult.
>
> I have already done the math by hand, and as I said it is
> straightforward, but I have more difficult minimizations I would like
> mathematica help me with.
>
> Best regards,
>
> Ola
>
--
DrMajorBob at longhorns.com