Re: [FRIAM] Optimization problem

Then there are those carefully selected branches from small trees or large bushes that  can be trimmed to size... watch out for poison oak! On 9/20/19 7:59 PM, Carl Tollander wrote: > Welding galvanized steel without proper respirators (even outdoors) > can kill you.  Research this carefully. > >

Re: [FRIAM] Optimization problem

You can splice together conduit pieces with set screw couplers. They're cheap, stable under compression loads, only require a screwdriver to operate, and produce no toxic gases. https://www.homedepot.com/p/Halex-3-4-in-Electrical-Metallic-Tube-EMT-Set-Screw-Coupling-25-Pack-62807B/202288563 --

Re: [FRIAM] Optimization problem

Welding galvanized steel without proper respirators (even outdoors) can kill you. Research this carefully. How about some nice thick wall pvc? Carl On Fri, Sep 20, 2019, 17:48 Steven A Smith wrote: > Gary - > > I understand better now... > > I definitely agree that the *most* naive

Re: [FRIAM] Optimization problem

Gary - I understand better now... I definitely agree that the *most* naive eyeballing methods can be excruciatingly wasteful. I presume that your conduit length requirements are not precise... that you might be designing them to allow for leaving the window partially open but otherwise not

Re: [FRIAM] Optimization problem

Steve, that makes my day! Your solution is like Kirk's way of passing the "Kobayashi Maru" training exercise. https://en.wikipedia.org/wiki/Kobayashi_Maru On Fri, Sep 20, 2019 at 6:23 PM Stephen Guerin wrote: > > Algorithm with guaranteed optimal: > > purchase ceil(TotalLengthNeeded / 6) tubes

Re: [FRIAM] Optimization problem

Algorithm with guaranteed optimal: 1. purchase ceil(TotalLengthNeeded / 6) tubes 2. Weld purchased tubes into one long tube * 3. Cut what you need in any order * assumes welder $ < optimization design and compute time

Re: [FRIAM] Optimization problem

Marcus, for the couple of dozen pieces I need to cut, I suspect a purely brute force solution would be adequate. I've only begun to think about what an extremely naive algorithm would look like. On Fri, Sep 20, 2019 at 6:07 PM Marcus Daniels wrote: > > In my experience, general purpose

Re: [FRIAM] Optimization problem

Hey Steve. The actual project is nothing elaborate. My house has a couple or three dozsen horizontally sliding windows with pretty weak locks. Since I've had a couple of break-ins in the past, I decided that the easiest way to shore up security for that aspect of the house is to just cut short

Re: [FRIAM] Optimization problem

In my experience, general purpose constraint and SMT solvers tend to have poor performance compared to linear relaxation techniques found in mathematical optimization products like CPLEX (which also have constraints but from a limited repertoire). It depends on the nature of your constraints

Re: [FRIAM] Optimization problem

Gary - I *patently don't* recommend my method, though it does have some charms.   I recently was faced with a similar problem to yours where I needed to cut and install trim around the perimeter of the room (with door openings) I just layed hardwood floor in.   Rather than go into it in detail

Re: [FRIAM] Optimization problem

Thanks for the links, Peter. I will probably use that software or similar, to get a quick solution, then look at the MOOCs. On Fri, Sep 20, 2019 at 2:52 PM Pieter Steenekamp wrote: > > Two possible approaches are: > a) Solve the problem yourself. Use one or a combination of standard >

Re: [FRIAM] Optimization problem

And if you want to know how it works, I suggest SCIP. https://scip.zib.de/ From: Friam on behalf of Pieter Steenekamp Reply-To: The Friday Morning Applied Complexity Coffee Group Date: Friday, September 20, 2019 at 12:52 PM To: The Friday Morning Applied Complexity Coffee Group Subject:

Re: [FRIAM] Optimization problem

Two possible approaches are: a) Solve the problem yourself. Use one or a combination of standard algorithms ( eg you mentioned linear programming and greedy algorithms, there are many more of course) and/or your own custom algorithm. If you wish to go this route and want to learn about the

[FRIAM] Optimization problem

I'd like advice on possible ways to solve the following problem (plumbers must surely face this all the time). I need to cut a set of metal tubes of varying lengths from standard length (6 meter) galvanized conduit stock. The goal is to find the number of tubes I need to buy, and the order of cuts