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yadango

Member Since 23 Jul 2005
Offline Last Active Jul 04 2013 08:34 PM

Posts I've Made

In Topic: Minimal Path Problem

28 September 2012 - 06:45 PM

I'm struggling to follow your reasoning as to why you have to look backwards to determine the cost of the path going forwards. If your weights are done correctly, getting to node D includes the cost of getting to any of the previous nodes that made up the path. Unless your movement along the terrain can cause a landslide that affects the path ahead I don't follow your line of thinking.


Correct. Yeah, if say using squared RMS (square of euclidean distance), you really pay for doing large uphills in the first place, so even something simple like that should take care of things like the one large hill + one small hill is worse than two medium size hills of the same distance problem. I was just trying to extend the problem in a different way to see where I could go with it he he he.

So in general, after reading the research on these types of problems, I've accepted that you should never break Bellman's Principle unless you absolutely have to. It's fun stuff though... there are some really interesting problems that break Bellman's Principle (mainly time-based things like traffic and music performance).

In Topic: Minimal Path Problem

27 September 2012 - 11:39 AM

Thanks alvaro,

Thanks to you guys I think I found a journal article on the topic: "Finding the Shortest Path in Dynamic Network using Labeling Algorithm." The thing I was looking for was a shortest path algorithm with "nondeterministic weights." The problem is actually quite common (happens with traffic as weights change with time) and has a ton of research published on it. I thought the problem I mentioned might be intractable too but it turns out it is not Posted Image. It says that as long as the weights are known ahead of time (not random as with traffic and can be listed or represented using a function), the problem is not intractable. Posted Image Though, yeah, having to backtrack to find out what the possible weights are is going to slow down an already slow polynomial time algorithm he he he.

Thanks!

In Topic: Minimal Path Problem

27 September 2012 - 03:20 AM

Exactly guys! You guys are all right on it... it would either require a massive expansion of nodes or probably a metaheuristic to solve! I'm just silly lol. Ever had that thought where you say ok I'm going to add a little twist to an existing problem to see if I can get better results only to find out that what you're trying to do is silly or impossible :-)? I'm surprised I couldn't find anything on google about this type of problem... "Graph" "shortest path" "multiple weights" "conditional weights" etc... turned up nothing!

In Topic: win32 dialog question

12 August 2012 - 11:30 AM

Why not call DialogBox after calling CreateWindow? That will show your modal dialog and window at the same time. I don't think there's a way to do it from a window proc, albeit using timers. However your first post indicates you are calling CreateDialog and using it in combination with EndDialog, which is incorrect usage. CreateDialog also shouldn't hide your parent window. You should post your sample source so we can pick it apart.

In Topic: Thanks Game Dev

10 August 2012 - 01:41 AM

C# is it's own language... I wouldn't say it's an exact combination of anything because the libraries and many components such as generics are quite different. It came about out of the Sun-Microsoft fiasco many years back over the language known as J++ or something like that. They hired the guy from Borland/Inprise who created Delphi to construct a new language similar to Java with the benefits of Delphi (some people consider the VCL a precursor to the FCL). So C# is really, if anything, a Java/Delphi hybrid he he he. C# was dubbed the Java-Killer for a long time but it didn't really kill Java; you could say it killed Delphi though.

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