y in English. ○Presenter
Robert (Bob) McNeel (McNeel & Associates founder) Robert (Bob) McNeel is the founder and president of Robert McNeel & Associates (RMA). Founded in 1978, RMA originally focused on developing accounting software for accounting, architecture, engineering, and other personal services firms. Within a few years, RMA expanded its services to include selling and supporting microprocessor-based engineering and design software including AutoCAD. By 1985, the main focus of the business had shifted to AutoCAD sales, service, training, and software development. Bob McNeel grew up in the mountains of southern Washington State on a subsistence dairy farm. To pay for college, he worked in construction as a carpenter, welder, and cement finisher. Bob has a BA in Accounting from Washington State University. Prior to founding McNeel & Associates, he was a practicing Certified Public Accountant and the comptroller for a large construction company in Spokane. Andrés González (Rhino Fablab director) Andrés is a software trainer and developer since the 1980s. He has developed applications for diverse design markets as well as training materials for different CAD and Design software including the community of training materialswww.Rhino3D.TV Andrés has been working with the Rhino Team since the very early stages. He is now the head of the McNeel Southeast US & Latin American Division. He is the worldwide director of the digital fabrication community called RhinoFabLabwww.RhinoFabLab.com as well as the Generative Jewelry & Fashion Design community GJD3D www.GJD3d.com and Generative Furniture Design community GFD3D www.GFD3d.com 1981 -1985 University of North Carolina at Charlotte N.C. - EE.UU. B.S., Bachelor of Science in Engineering
…
Added by Yusuke Oono at 9:28pm on October 16, 2013
ating to new speakers.
For more information: https://medium.com/@carspeakerland/a-guide-to-the-simple-way-difference-in-car-speakers-2-way-3-way-4-way-25e0bf215b00
Adding new speakers for your automobile could improve the sound quality dramatically. Some sound technicians say it is the number-one update you may make to improve the overall quality of your vehicle.
"They do not care how it sounds. Speakers are often form of continue on the list. Updating to new speakers offers you a much fuller sound."
There is a whole lot to pick from in regards to car speakers. (Photo from Eldon Lindsay)
"New speakers will make a greater fidelity and clarity of sound," states Robert Nevitt, proprietor of Audio Electronics at Indianapolis. "The audio is more different without distortion. People will not get bored listening to it."
Cook says customers need to pick the type of sound they enjoy. The very first thing Cook does having a customer is sit in the car together to talk about their personal taste.
"Everybody's ear is different," he states. "That which I believe sounds great, you might believe is dreadful. It is a fantastic idea to get outside and listen to everything you enjoy and do not like about doing it."
When you've discovered a sound you want, you are going to discover the sky's actually the limitation in regards to purchasing car speakers. There are scores of manufactures and models, sizes and power levels to select from.
Columbus Car Audio & Accessories offers three types of automobile speakers to pick from: complete array speakers, component speakers along with coaxial speakers.
• Total range speakers arrive with a tweeter to make to your high-pitched sounds along with a woofer for those lows. This option offers a number of different sizes.
• Unit speakers, nonetheless, include separate tweeters and woofers.
• Coaxial speakers arrive with a tweeter plus motorist.
When you've selected a type of automobile speaker, you are going to want to determine how many you desire. Cook states some cars arrive with as little as just two speakers, whereas bigger, luxury vehicles might have too many 32. He adds a normal sedan generally has four. What are The Speaker Sizes in My Car | Speaker Size for My Car
"It simply depends if you would like to replace all of these," Cook says. "I would advise doing all of four. If you are budget-minded, I'd begin with the ones at the front. That is where you are at. And you are likely to be at the automobile 100 percent of their moment."
Subwoofers are designed to reproduce low bass frequencies also may be included with new speakers or could be added separately to existing car speakers.
"Many speakers can not play down low in these frequencies such as a subwoofer may," Cook says.
Related Article
Wondering about speakers? Below are a few techniques to establish a home entertainment experience whatever your budget.
A speaker update might charge as little as $100 up to a few million dollars depending on the scope of job and type of speaker.
Cook states that the price of a subwoofer can operate as low as $37. Columbus Car Audio & Accessories sells a subewoofer bundle that includes an amplifier and a enclosure for about $ 299.
To get a set of automobile speakers, Columbus Car Audio & Accessories begin prices at $39, with an average price tag of about $70 for setup. Adding an anti-vibrator into a set of speakers prices an additional $25.
Nevitt, meanwhile, fees as little as $99 to get a set of "some good speakers." The price of one hour of installion, that is typically how long it takes to put in a set of speakers, is 67.
However, most customers spend far more.
"Paying a total amount of 800 to $1000 isn't from this world of possibility," Nevitt states. "A price somewhere in the center could be $400 or $500."
Cook says several vehicle speaker technicians began with DIY projects and adds there is nothing wrong with trying to set up car speakers all on your own. But you are going to want the correct tools for your job along with just a little understand. Installing speakers requires carrying out your car door.
See Also: https://www.scoop.it/t/how-to-choose-best-car-speakers-6x9-inch-6-5-inch-6x8-inch-4-inch
Choosing a professional to set up speakers ensures that the job is done correctly.
"If you do it yourself, then you might wind up breaking something. That is some thing we do everyday. I am not planning to inform you we will not violate something. But we will look after it if we perform. We all do so with being honest and up front with people."
If you are getting speakers set up, experts say to expect to place an appointment to the setup. …
DP ($$$ aside), GC, and Grasshopper. Arthur’s original question is very important
and the exact question (and hopefully answer) I was hoping to find on a
forum.
“How to take intelligent 3D parametric generative design models (scripting, etc.) into 2D documents?" Or, deliver the 3D design for evaluation, bid, construction, etc.
I am intrigued by Jon’s comments in the same thread and would like to know how I can learn more about the process (and
pitfalls) of turning over a 3D digital generative models to a contractor/fabricator.
Are there any industry guidelines established I could use as a reference to guide our firm through this type of uncharted territory?
Arthur’s question is very reminiscent of 10 years ago when I was frustrated with the amount of time spent on the development of a 3D model design (physical and/or virtual) only to have to wipe the table clean and start the process all over again in 2D in order to document the project for delivery. From this I jumped head first into BIM and Revit, vowing never to go back to unintelligent 2D line work. I am now working on Bentley software (v8i: Microstation and Bentley Architecture) with the access and desire to venture into Generative Components. I am very intrigued by Rhino/Grasshopper primarily with the apparent ease of use and available resources assisting in the learning process – something not really available with Bentley.
In hindsight, as I am doing my software research I think the current use of Revit and BA (Bentley Architecture) are more of a “bridge”
between the past (decades of digital 2D work, i.e. AutoCAD) and where hopefully
we all will be someday in the near future (100% 3D modeling, i.e. Digital
Project??). Without having the experience
it would appear that DP/CATIA (PLM software) are closer to this than any other
type of software. As complicated as the
industry standards are for the automobile and airline industry, I feel we
(architectural industry and others) are heading in a similar direction with
total understanding (PLM/ Evidence Based Design) of a design (a whole other topic). If anything I think the market will begin to
demand it sooner or later.
Gehry (DP) article NY Times:
http://www.nytimes.com/2009/02/11/business/11gehry.html
I know these type of broad discussions (software vs. software) can be blown out of proportion on forums, but I am would like to read
the pulse of those who are already in the trenches (using Grasshopper, CATIA, Digital Project, Generative Components, others??) and hear your thoughts. Just as valuable would be other threads,
industry articles/reviews of 3D parametric generative design software.
Thanks,
Boyd…
.
Things have been working swimmingly in many areas of the plugin, but one particular problem has been tough to solve. I have two components that are trying to read/write to the same memory at the same time, causing Rhino exceptions and crashes.
The conflicts appear to be happening between two components -- one is a "Layer Events Listener" that reports essentially what type of layer event just happened. The other is a "Set Layer Visibility" component that toggles the visibility of a list of layers.
The code:
public class LayerTools_LayerEventsListener : GH_Component { /// <summary> /// Initializes a new instance of the LayerTools_LayerListener class. /// </summary> public LayerTools_LayerEventsListener() : base("Layer Events Listener", "Layer Listener", "Get granular information about the layer events happening in the Rhino document.", "Squirrel", "Layer Tools") { }
/// <summary> /// Registers all the input parameters for this component. /// </summary> protected override void RegisterInputParams(GH_Component.GH_InputParamManager pManager) { pManager.AddBooleanParameter("Active", "A", "Set to true to listen to layer events in the Rhino document.", GH_ParamAccess.item, false); pManager.AddTextParameter("Exclusions", "E", "Provide a list of exclusions to stop reading specific events (Added, Deleted, Moved, Renamed, Locked, Visibility, Color, Active).", GH_ParamAccess.list); pManager[1].Optional = true; }
/// <summary> /// Registers all the output parameters for this component. /// </summary> protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager) { pManager.AddBooleanParameter("Initialized", "I", "Whether the listener changed from passive to active.", GH_ParamAccess.item); pManager.AddTextParameter("Document Name", "doc", "Name of the Rhino document that is changing.", GH_ParamAccess.item); pManager.AddTextParameter("Layer Path", "path", "Path of the modifed layer.", GH_ParamAccess.item); pManager.AddIntegerParameter("Layer Index", "ID", "Index of the modified layer.", GH_ParamAccess.item); pManager.AddIntegerParameter("Sort Index", "SID", "Sort index of the modified layer.", GH_ParamAccess.item); pManager.AddTextParameter("Event Type", "T", "Type of the modification.", GH_ParamAccess.item); pManager.AddBooleanParameter("Added", "A", "If the layer has been added.", GH_ParamAccess.item); pManager.AddBooleanParameter("Deleted", "D", "If the layer has been deleted.", GH_ParamAccess.item); pManager.AddBooleanParameter("Moved", "M", "If the layer has been moved.", GH_ParamAccess.item); pManager.AddBooleanParameter("Renamed", "R", "If the layer has been renamed.", GH_ParamAccess.item); pManager.AddBooleanParameter("Locked", "L", "If the layer locked setting has changed.", GH_ParamAccess.item); pManager.AddBooleanParameter("Visibility", "V", "If the layer's visibility has changed.", GH_ParamAccess.item); pManager.AddBooleanParameter("Color", "C", "If the layer's color has changed.", GH_ParamAccess.item); pManager.AddBooleanParameter("Active", "Act", "If the active layer has changed.", GH_ParamAccess.item); }
/// <summary> /// This is the method that actually does the work. /// </summary> /// <param name="DA">The DA object is used to retrieve from inputs and store in outputs.</param> protected override void SolveInstance(IGH_DataAccess DA) { bool active = false; List<string> exclusions = new List<string>();
DA.GetData(0, ref active); DA.GetDataList(1, exclusions);
RhinoDoc thisDoc = null;
bool initialize = false;
string dName = null; string activePath = null; int layerIndex = -1; int sortIndex = -1; string eventType = null; bool added = false; bool deleted = false; bool moved = false; bool renamed = false; bool locked = false; bool visibility = false; bool color = false; bool current = false;
if (active) { thisDoc = RhinoDoc.ActiveDoc;
initialize = (!previouslyActive) ? true : false;
RhinoDoc.LayerTableEvent -= RhinoDoc_LayerTableEvent; RhinoDoc.LayerTableEvent += RhinoDoc_LayerTableEvent; previouslyActive = true;
} else {
RhinoDoc.LayerTableEvent -= RhinoDoc_LayerTableEvent; previouslyActive = false; }
if (ev != null) { dName = ev.Document.Name; layerIndex = ev.LayerIndex; eventType = ev.EventType.ToString();
if (!exclusions.Contains("Active")) { if (ev.EventType.ToString() == "Current") { // active layer has just been changed current = true; }
}
if (!exclusions.Contains("Moved")) { if (ev.EventType.ToString() == "Sorted") { // active layer has just been changed moved = true; }
}
if (!exclusions.Contains("Added")) { if (ev.EventType.ToString() == "Added") { // layer has just been added activePath = ev.NewState.FullPath; added = true; }
}
if (!exclusions.Contains("Active")) { if (ev.EventType.ToString() == "Deleted") { // layer has just been added
deleted = true; } }
if (ev.EventType.ToString() == "Modified") { // layer has been modified activePath = ev.NewState.FullPath;
//skip sortindex eventType = ev.EventType.ToString();
if (ev.OldState != null && ev.NewState != null) { if (!exclusions.Contains("Locked")) { if (ev.OldState.IsLocked != ev.NewState.IsLocked) locked = true;
} if (!exclusions.Contains("Visibility")) { if (ev.OldState.IsVisible != ev.NewState.IsVisible) visibility = true; }
if (!exclusions.Contains("Moved")) { if (ev.OldState.ParentLayerId != ev.NewState.ParentLayerId) moved = true; }
//if (ev.OldState.SortIndex != ev.NewState.SortIndex) moved = true; if (!exclusions.Contains("Renamed")) { if (ev.OldState.Name != ev.NewState.Name) renamed = true; }
if (!exclusions.Contains("Color")) { if (ev.OldState.Color != ev.NewState.Color) color = true; } }
} }
DA.SetData(0, initialize); DA.SetData(1, dName); DA.SetData(2, activePath); DA.SetData(3, layerIndex); DA.SetData(4, sortIndex); DA.SetData(5, eventType); DA.SetData(6, added); DA.SetData(7, deleted); DA.SetData(8, moved); DA.SetData(9, renamed); DA.SetData(10, locked); DA.SetData(11, visibility); DA.SetData(12, color); DA.SetData(13, current);
}
static bool previouslyActive = false; Rhino.DocObjects.Tables.LayerTableEventArgs ev = null;
void RhinoDoc_LayerTableEvent(object sender, Rhino.DocObjects.Tables.LayerTableEventArgs e) { ev = e;this.ExpireSolution(true); }
And for the layer visibility component:
public LayerTools_SetActiveLayer() : base("Set Active Layer", "SetActiveLayer", "Set the active layer in the Rhino document.", "Squirrel", "Layer Tools") { }
/// <summary> /// Registers all the input parameters for this component. /// </summary> protected override void RegisterInputParams(GH_Component.GH_InputParamManager pManager) { pManager.AddBooleanParameter("Active", "A", "Set to true to change the active layer in Rhino.", GH_ParamAccess.item, false); pManager.AddTextParameter("Path", "P", "Full path of the layer to be activated.", GH_ParamAccess.item); }
/// <summary> /// Registers all the output parameters for this component. /// </summary> protected override void RegisterOutputParams(GH_Component.GH_OutputParamManager pManager) { pManager.AddIntegerParameter("Layer ID", "ID", "Index of layer that has been activated.", GH_ParamAccess.item); pManager.AddBooleanParameter("Status", "St", "True when the layer has been activated.", GH_ParamAccess.item); }
/// <summary> /// This is the method that actually does the work. /// </summary> /// <param name="DA">The DA object is used to retrieve from inputs and store in outputs.</param> protected override void SolveInstance(IGH_DataAccess DA) { bool active = false; string path = "";
if (!DA.GetData(0, ref active)) return; if (!DA.GetData(1, ref path)) return;
int layer_index = -1; bool status = false;
if (path != null) {
Rhino.RhinoDoc doc = Rhino.RhinoDoc.ActiveDoc; Rhino.DocObjects.Tables.LayerTable layertable = doc.Layers;
layer_index = layertable.FindByFullPath(path, true);
if (layer_index > 0) { // if exists RhinoDoc.ActiveDoc.Layers.SetCurrentLayerIndex(layer_index, true); status = true; } }
DA.SetData(0, layer_index); DA.SetData(1, status); }
Now originally I was getting exceptions when changing multiple layers' visibility properties, which would cause the Event Listener to fire and try to read the Visibility property before the memory has been released by the Set Layer Visibility component. That led me to add an "Exceptions" input, that would allow me to disable the reading of Visibility events at the source in the Layer Events listener. That helped me manage about 95% of the crashes I was getting, but I still get strange crashes in other event properties, even when that property shouldn't be affected. For instance, I am getting a crash here on the Name property in the event from the delegate function, even though I am only changing Visibility at any one time:
I have a few ideas but they all seem pretty hacky. One is to try to set a flag that is readable by any component in the plugin -- so that the event listener can see if a "set" component is currently running and abort before causing an exception. The other is creating a delay in the event listener, somthing like 200ms, to allow any set components to finish what they are doing before reading the event. Neither seems super ideal.
Any ideas?
Thanks,
Marc
…
This blog post is a rough approximation of the lecture I gave at the AAG10 conference in Vienna on September 21st 2010. Naturally it will be quite a different experience as the medium is quite…
Added by David Rutten at 3:27pm on September 24, 2010
currently within a fake euphoria framework - blame China/UAE) and a potential decision about doing/developing this or doing that … well …anyway … read and enjoy.
AEC matters: The good, the bad and the ugly.
The bad news: Rhino is NOT suitable for the job (although some use it … but only in the sense that people use Modo for the so called “hard modeling”). By job I mean things up to shop drawing level + specs + you and me (we call it Final level) – nothing to do with sketches and outlines of some abstract “schematic” topology.
The ugly news: The so called Design-Construct approach gains exponentially momentum especially in countries the likes of China/UAE/BRICS (95% of the whole AEC activity worldwide happens there). DeCo means: AEC engineers deliver some kind of study in a preliminary level and the main contractor splits (outsourcers) the job and assigns the study completion AND the construction to various sup-constructors. That thing appeared first – in a large scale - in Dubai 15 years ago. This means that the era of Sergio Pininfarina is over and out: welcome anonymous Toyota designer. In plain English: days of construction corporations fast replacing practices. Dead men walking.
The good news: All AEC related apps (Revit, AECOsim, Allplan and the likes) are in a lethargic state as regards the brave new world (based on the archaic level driven organization schemas etc etc). Of course they all claim the exact opposite and point that support BIM (nobody mention PLM) better than the other guy. But the 21st century – helped by 2 forthcoming unavoidable crisis (a) about shortage of water (b) about transition from carbon to hydrogen economy – isn’t about bureaucracy: think cost/resources optimization and “fitness” rather than China/UAE type of liquid trend. Days of euphoria fast approaching the Wall.
Top to bottom and visa versa.
Old days Titans (Oscar, Mies, Walter, Pierre Luigi, Frank, Eero, blah blah) outlined things (mostly using crayons) and the rest were struggling to translate these in reality in an one way vector like process : Top to bottom that is. These days the inverse gains momentum : when in the whole consider the part … validate … redo … validate … redo. This means bottom to top geared with top-to-bottom. In plain English : child imposes rules to parent and parent imposes rules to child. This means classic MCAD feature/history modeling (CATIA/NX/MS). This is something that Rhino can’t do (not to mention that Rhino is a surface modeler – a rather critical fact).
The parts that are bigger than the whole.
Go there ( http://www.behance.net/gallery/2885057/a-myriad-of-cables) are inspect the whole thing: it’s a parametric nightmare made with the other guy (Generative Components – slower than a Skoda + bugs + why bother?). But the whole (masts and membranes and the likes) means nothing here: focus to the details that are critical for connecting this with that. Complex feature driven solids that are made with internal (on a per se basis) parameters (like fillets required for casting or radius for cable anchoring) whilst they comply with external rules/parameters (cable angles, topology clash issues etc etc). So the whole outlines possibilities … and the part either can follow…or the part must change…or the whole must change. Can you do that with GH/Rhino? And if not what’s missing? (lot’s of things to be honest).
Some other "similar" things:
The narrow picture.
I agree with what others already said and with pretty much all Ola’s points – especially the visual drag-and-drop path mapper (i.e. a visual data manipulator so to speak) and the enable/disable components in groups capability.
Some other suggestions:
A multi canvas capability. As things are right now…it’s like working in Rhino in one view (rather unsuitable I guess). In fact …since overlapping views they don’t work in Rhino…well…you know, he he.
A working auto profile arrangement capability (non twisted Loft/Sweep and the likes). Worth 1Bn dollars that one.
Ability to locate components that caused this or that in the Rhino view: meaning a 2 way communication approach : GH makes things happen in Rhino and things can indicate their cause in the GH canvas.
A robust collection of components that bake stuff in nested blocks (emulating some primitive assembly/component way of thinking). Why may you ask? Well … the whole objective is to talk to CATIA (via STEP) don’t you agree? CATIA makes things happen in real-life not Rhino.
A robust collection of components that can create real-life parametric tensile membrane solutions (get some inspiration from FormFinder: useless because it’s academic but good to point the way). Membranes (and geodesics) are the future.
I could continue at infinitum but IMHO the big picture is worth 12345,67 “focused” GH improvements.
May the Force (the dark option) be with us all.
…
lly it should not make much of a difference - random number generation is not affected, mutation also is not. crossover is a bit more tricky, I use Simulated Binary Crossover (SBX-20) which was introduced already in 1194:
Deb K., Agrawal R. B.: Simulated Binary Crossover for Continuous Search Space, inIITK/ME/SMD-94027, Convenor, Technical Reports, Indian Institue of Technology, Kanpur, India,November 1994
Abst ract. The success of binary-coded gene t ic algorithms (GA s) inproblems having discrete sear ch sp ace largely depends on the codingused to represent the prob lem variables and on the crossover ope ratorthat propagates buildin g blocks from pare nt strings to childrenst rings . In solving optimization problems having continuous searchspace, binary-co ded GAs discr et ize the search space by using a codingof the problem var iables in binary st rings. However , t he coding of realvaluedvari ables in finit e-length st rings causes a number of difficulties:inability to achieve arbit rary pr ecision in the obtained solution , fixedmapping of problem var iab les, inh eren t Hamming cliff problem associatedwit h binary coding, and processing of Holland 's schemata incont inuous search space. Although a number of real-coded GAs aredevelop ed to solve optimization problems having a cont inuous searchspace, the search powers of these crossover operators are not adequate .In t his paper , t he search power of a crossover operator is defined int erms of the probability of creating an arbitrary child solut ion froma given pair of parent solutions . Motivated by t he success of binarycodedGAs in discret e search space problems , we develop a real-codedcrossover (which we call the simulated binar y crossover , or SBX) operatorwhose search power is similar to that of the single-point crossoverused in binary-coded GAs . Simulation results on a number of realvaluedt est problems of varying difficulty and dimensionality suggestt hat the real-cod ed GAs with t he SBX operator ar e ab le to perform asgood or bet t er than binary-cod ed GAs wit h t he single-po int crossover.SBX is found to be particularly useful in problems having mult ip le optimalsolutions with a narrow global basin an d in prob lems where thelower and upper bo unds of the global optimum are not known a priori.Further , a simulation on a two-var iable blocked function showsthat the real-coded GA with SBX work s as suggested by Goldberg
and in most cases t he performance of real-coded GA with SBX is similarto that of binary GAs with a single-point crossover. Based onth ese encouraging results, this paper suggests a number of extensionsto the present study.
7. ConclusionsIn this paper, a real-coded crossover operator has been develop ed bas ed ont he search characte rist ics of a single-point crossover used in binary -codedGAs. In ord er to define the search power of a crossover operator, a spreadfactor has been introduced as the ratio of the absolute differences of thechildren points to that of the parent points. Thereaft er , the probabilityof creat ing a child point for two given parent points has been derived forthe single-point crossover. Motivat ed by the success of binary-coded GAsin problems wit h discrete sear ch space, a simul ated bin ary crossover (SBX)operator has been develop ed to solve problems having cont inuous searchspace. The SBX operator has search power similar to that of the single-po intcrossover.On a number of t est fun ctions, including De Jong's five te st fun ct ions, ithas been found that real-coded GAs with the SBX operator can overcome anumb er of difficult ies inherent with binary-coded GAs in solving cont inuoussearch space problems-Hamming cliff problem, arbitrary pr ecision problem,and fixed mapped coding problem. In the comparison of real-coded GAs wit ha SBX operator and binary-coded GAs with a single-point crossover ope rat or ,it has been observed that the performance of the former is better than thelatt er on continuous functions and the performance of the former is similarto the lat ter in solving discret e and difficult functions. In comparison withanother real-coded crossover operator (i.e. , BLX-0 .5) suggested elsewhere ,SBX performs better in difficult test functions. It has also been observedthat SBX is particularly useful in problems where the bounds of the optimum
point is not known a priori and wher e there are multi ple optima, of whichone is global.Real-coded GAs wit h t he SBX op erator have also been tried in solvinga two-variab le blocked function (the concept of blocked fun ctions was introducedin [10]). Blocked fun ct ions are difficult for real-coded GAs , becauselocal optimal points block t he progress of search to continue towards t heglobal optimal point . The simulat ion results on t he two-var iable blockedfunction have shown that in most occasions , the sea rch proceeds the way aspr edicted in [10]. Most importantly, it has been observed that the real-codedGAs wit h SBX work similar to that of t he binary-coded GAs wit h single-pointcrossover in overcoming t he barrier of the local peaks and converging to t heglobal bas in. However , it is premature to conclude whether real-coded GAswit h SBX op erator can overcome t he local barriers in higher-dimensionalblocked fun ct ions.These results are encour aging and suggest avenues for further research.Because the SBX ope rat or uses a probability distribut ion for choosing a childpo int , the real-coded GAs wit h SBX are one st ep ahead of the binary-codedGAs in te rms of ach ieving a convergence proof for GAs. With a direct probabilist ic relationship between children and parent points used in t his paper,cues from t he clas sical stochast ic optimization methods can be borrowed toachieve a convergence proof of GAs , or a much closer tie between the classicaloptimization methods and GAs is on t he horizon.
In short, according to the authors my SBX operator using real gene values is as good as older ones specially designed for discrete searches, and better in continuous searches. SBX as far as i know meanwhile is a standard general crossover operator.
But:
- there might be better ones out there i just havent seen yet. please tell me.
- besides tournament selection and mutation, crossover is just one part of the breeding pipeline. also there is the elite management for MOEA which is AT LEAST as important as the breeding itself.
- depending on the problem, there are almost always better specific ways of how to code the mutation and the crossover operators. but octopus is meant to keep it general for the moment - maybe there's a way for an interface to code those things yourself..!?
2) elite size = SPEA-2 archive size, yes. the rate depends on your convergence behaviour i would say. i usually start off with at least half the size of the population, but mostly the same size (as it is hard-coded in the new version, i just realize) is big enough.
4) the non-dominated front is always put into the archive first. if the archive size is exceeded, the least important individual (the significant strategy in SPEA-2) are truncated one by one until the size is reached. if it is smaller, the fittest dominated individuals are put into the elite. the latter happens in the beginning of the run, when the front wasn't discovered well yet.
3) yes it is. this is a custom implementation i figured out myself. however i'm close to have the HypE algorithm working in the new version, which natively has got the possibility to articulate perference relations on sets of solutions.
…