doing this with the current tools or a bit of scripting since the Flickr API allows you to make requests in a REST format, but utilizing the Flickr.net API library makes it much simpler.
First and foremost, you need a Flickr API key...do you have one of those?
A great way to get to know the Flickr API is with the API Explorer. Here is a link to the page for the flickr.photos.search method explorer: http://www.flickr.com/services/api/explore/flickr.photos.search
The cool thing about this page is that it generates the REST Http call towards the bottom. So, here is what I did:
1. Grab the coordinates of the bounding box per Flickr API request:
bbox (Optional)
A comma-delimited list of 4 values defining the Bounding Box of the area that will be searched. The 4 values represent the bottom-left corner of the box and the top-right corner, minimum_longitude, minimum_latitude, maximum_longitude, maximum_latitude. Longitude has a range of -180 to 180 , latitude of -90 to 90. Defaults to -180, -90, 180, 90 if not specified. Unlike standard photo queries, geo (or bounding box) queries will only return 250 results per page. Geo queries require some sort of limiting agent in order to prevent the database from crying. This is basically like the check against "parameterless searches" for queries without a geo component. A tag, for instance, is considered a limiting agent as are user defined min_date_taken and min_date_upload parameters — If no limiting factor is passed we return only photos added in the last 12 hours (though we may extend the limit in the future).
So, I went to Google Earth, picked a city (London, UK) and dropped two pins:
This gave me two locations, which I can put into the Explorer Page next to the bbox option. Here is what I put for these two points: -0.155941,51.496768,-0.116783,51.511431
2. Check has_geo
3. In extras, type in geo
4. Make the call!
You will see a list of responses in an XML format, these responses will be from the first page. Geolocated photos are limited to 250 / page, so you will have to grab them page by page.
If you want to add more options (minimum upload date, maximum upload date, etc) you can do this as well)
The best is at the bottom, you get the full http call for this: http://api.flickr.com/services/rest/?method=flickr.photos.search&api_key=ffd44f601393a46e86aa3a5f8a013360&bbox=-0.155941%2C51.496768%2C-0.116783%2C51.511431&has_geo=&extras=geo&format=rest&api_sig=b42330e5d1523bd5fe60c2ad43acde99
Notice this call has some other api key, you should eventually replace this with your own.
You could copy and paste this into a browser and you will get the results with the latitude and longitude:
So this is really what you need to know to do this through GH. Since gHowl has an XML parser component that can access files on the web, you should be able to use the same http call into this component.
Eventually, we get a response, and we need to grab the lat and lon data. With gHowl we can map these to xyz coordinates, and generate the heatmap...this is just a linear mapping:
Attached are both the Rhino file and the Grasshopper file, as well as the image underlay.
I am working on a series of components that makes this more straightforward, but for now, this should get you started.
…
peuvent se diviser une surface avec ne importe quel motif imaginable. 3. Ici, je fournir un moyen de le faire via Lunchbox ... cela fonctionne mais il est fixe et donc nous avons besoin de jouer avec des arbres de données afin de créer le motif approprié par cas. 4. L'autre composante est un joint C # qui fait beaucoup de choses autres que de diviser ne importe quelle collection de points avec de nombreux modèles (voir le modèle ANDRE que je ai fait pour vous). 5. Vous devez décomposer une polysurface en morceaux afin de travailler sur les subdivisions. 6. Je donne une autre définition ainsi que pourrait agir comme un tutoriel sur la façon de traiter des ensembles de points via des composants de GH standards et des méthodes classiques.
Avertissez si tous ceux-ci apparaissent floue pour vous: Si oui, je pourrais écrire une définition utilisant des composants de GH classiques - mais vous perdrez les variations de motifs de division.
mieux, Peter
…
and export the geometry out to VVVV to render it LIVE! RawRRRR. In this case, a digital audio workstation Ableton Live, a leading industrial standard in contemporary music production.
the good news is that VVVV and ableton live lite is both free.
https://www.ableton.com/en/products/live-lite/
i am not trying to use ipad as a controller for grasshoppper. I wanted to work with a timeline (similar to MAYA or Ableton or any other DAW(digital audio workstation)) inside grasshopper in an intuitive way. Currently there is no way of SEQUENCING your definition the way you want to see that i know of.
no more combersome export import workflows... i dont need hyperrealistic renderings most of the time. so much time invested in googling the right way to import, export ... mesh settings...this workflow works for some, for some not ...that workflow works if ... and still you cannot render it live nor change sequence of instruction WHILE THE VIDEO is played. and I think no one wants to present rhinoceros viewport. BUT vvvv veiwport is different. it is used for VJing and many custom audio visual installation for events, done professionally. you can see an example of how sound and visuals come together from this post, using only VVVV and ableton. http://vvvv.org/documentation/meso-amstel-pulse
I propose a NEW method. make a definition, wire it to ableton, draw in some midi notes, and see it thru VVVV LIVE while you sequence the animation the WAY YOU WANT TO BE SEEN DURING YOUR PRESENTATION FROM THE BEGINNING, make a whole set of sequences in ableton, go back change some notes in ableton and the whole sequence will change RIGHT INFRONT of you. yes, you can just add some sound anywhere in the process. or take the sound waves (sqaure, saw, whateve) or take the audio and influence geometric parameters using custom patches via vvvv. I cannot even begin to tell you how sophisticated digital audio sound design technology got last ten year.. this is just one example which isn't even that advanced in todays standard in sound design ( and the famous producers would say its not about the tools at all.) http://www.youtube.com/watch?v=Iwz32bEgV8o
I just want to point out that grasshopper shares the same interface with VVVV (1998) and maxforlive, a plug in inside ableton. audio mulch is yet another one that shares this interface of plugging components to each other and allows users to create their own sound instruments. vvvv is built based on vb, i believe.
so current wish list is ...
1) grasshopper recieves a sequence of commands from ableton DONE
thanks to sebastian's OSCglue vvvv patch and this one http://vvvv.org/contribution/vvvv-and-grasshopper-demo-with-ghowl-udp
after this is done, its a matter of trimming and splitting the incoming string.
2) translate numeric oscillation from ableton to change GH values
video below shows what the controll interface of both values (numbers) and the midi notes look like.
https://vimeo.com/19743303
3) midi note in = toggle GH component (this one could be tricky)
for this... i am thinking it would be great if ...it is possible to make "midi learn" function in grasshopper where one can DROP IN A COMPONENT LIKE GALAPAGOS OR TIMER and assign the component to a signal in, in this case a midi note. there are total 128 midi notes (http://www.midimountain.com/midi/midi_note_numbers.html) and this is only for one channel. there are infinite channels in ableton. I usually use 16.
I have already figured out a way to send string into grasshopper from ableton live. but problem is, how for grasshopper to listen, not just take it in, and interpret midi and cc value changes ( usually runs from 0 to 128) and perform certain actions.
Basically what I am trying to achieve is this : some time passes then a parameter is set to change from value 0 to 50, for example. then some time passes again, then another parameter becomes "previewed", then baked. I have seen some examples of hoopsnake but I couldn't tell that you can really control the values in a clear x and y graph where x is time and y is the value. but this woud be considered a basic feature of modulation and automation in music production. NVM, its been DONE by Mr Heumann. https://vimeo.com/39730831
4) send points, lines, surfaces and meshes back out to VVVV
5) render it using VVVV and play with enormous collection of components in VVVV..its been around since 1998 for the sake of awesomeness.
this kind of a digital operation-hardware connection is usually whats done in digital music production solutions. I did look into midi controller - grasshopper work, and I know its been done, but that has obvious limitations of not being precise. and it only takes 0 o 128. I am thinking that midi can be useful for this because then I can program very precise and complex sequence with ease from music production software like ableton live.
This is an ongoing design research for a performative exhibition due in Bochum, Germany, this January. I will post definition if I get somewhere. A good place to start for me is the nesting sliders by Monique . http://www.grasshopper3d.com/forum/topics/nesting-sliders
…
ers can be applied from the right click Context Menu of either a component's input or output parameters. With the exception of <Principal> and <Degrees> they work exactly like their corresponding Grasshopper Component. When a I/O Modifier is applied to a parameter a visual Tag (icon) is displayed. If you hover over a Tag a tool tip will be displayed showing what it is and what it does.
The full list of these Tags:
1) Principal
An input with the Principal Icon is designated the principal input of a component for the purposes of path assignment.
For example:
2) Reverse
The Reverse I/O Modifier will reverse the order of a list (or lists in a multiple path structure)
3) Flatten
The Flatten I/O Modifier will reduce a multi-path tree down to a single list on the {0} path
4) Graft
The Graft I/O Modifier will create a new branch for each individual item in a list (or lists)
5) Simplify
The Simplify I/O Modifier will remove the overlap shared amongst all branches. [Note that a single branch does not share any overlap with anything else.]
6) Degrees
The Degrees Input Modifier indicates that the numbers received are actually measured in Degrees rather than Radians. Think of it more like a preference setting for each angle input on a Grasshopper Component that state you prefer to work in Degrees. There is no Output option as this is only available on Angle Inputs.
7) Expression
The Expression I/O Modifier allows you change the input value by evaluating an expression such as -x/2 which will have the input and make it negative. If you hover over the Tag a tool tip will be displayed with the expression. Since the release of GH version 0.9.0068 all I/O Expression Modifiers use "x" instead of the nickname of the parameter.
8) Reparameterize
The Reparameterize I/O Modifier will only work on lines, curves and surfaces forcing the domains of all geometry to the [0.0 to 1.0] range.
9) Invert
The Invert Input Modifier works in a similar way to a Not Gate in Boolean Logic negating the input. A good example of when to use this is on [Cull Pattern] where you wish to invert the logic to get the opposite results. There is no Output option as this is only available on Boolean Inputs.
…
as one element.
Thank you
Comment by karamba on October 7, 2014 at 11:27pm
Hello Patricio, divide the beams in such a way that each boundary vertex of the shell becomes an endpoint of a beam segment.
Best, Clemens
Comment by Llordella Patricio on October 8, 2014 at 8:30amDelete Comment
Hi Clemens,
I did what you suggested but now assemble element doesn´t work properly. Could you please tell me how to fix it? Thanks in advance, Patricio
8-10-14losa%20cadena.gh
Comment by karamba on October 8, 2014 at 11:59am
Hi Patricio, if you flatten the 'Elem'-input at the 'Assemble'-component the definition works. The triangular shell elements have linear displacement interpolations whereas the beam deflections are exact. In order to get correct results you should refine the shell mesh.
Best, Clemens
Comment by Llordella Patricio on October 9, 2014 at 8:35amDelete Comment
Hello, succeeds in creating the mesh to the slab, and built the beam segment, but when I see the deformations are not expected because the beam is deformed as the slab.
Thanks for the help
PS: maybe I'm using the program for a type of structure that is not the most appropriate, as I saw in the examples of other structures. But this type of structure is that students taught
best regards
Patricio
9-10-14%20Example%201.gh
Comment by karamba on October 9, 2014 at 10:46am
You could use the 'Mesh Edges'-component to retrieve the naked edges and turn them into beams - see attached file:91014Example1_cp.gh
Best regards,
Clemens
Comment by Llordella Patricio on October 15, 2014 at 3:41pmDelete Comment
Dear clemens
I was doing a rough estimate of the deformation, and I can not achieve the same result with Karamba. When I make a rough estimate of the result with Karamba beams and mine are very similar, I think the problem is when I connect the shell, because there are no similar results.
I sent the GH file, and an image of the calculation
The structure is concrete The result I get is 0.58cm
thank youPatricio
15-10-14%20Example.gh
Comment by karamba yesterday
Dear Patricio,
try to increase the number of shell elements. As mentioned in the manual they are linear elements. A mesh that is too coarse leads to a response which is stiffer than the real structure.
Best,
Clemens
…
n be obtained for curved NURBS surfaces as well as unconventional window configurations".
And I also noticed the following information form the optional input in the runEnergySimulation component.
"meshSettings_: Optional mesh settings for your geometry from any one of the native Grasshopper mesh setting components. These will be used to change the meshing of curved surfaces before they are run through EnergyPlus (note that meshing of curved surfaces is done since Energyplus is not able to calculate heat flow through non-planar surfaces). Default Grasshopper meshing is used if nothing is input here but you may want to decrease your calculation time by changing it to Coarse or increase your curvature definition (and calculation time) by making it finer".
1) My case is an one-story, rectangular-plan large hall (40m*70m*25m) with a curved roof. The roof surface is a part of a standard sphere and the walls and floor are all planar (the each wall has one curved edge as showed in the image).
For testing, I threw the original curved roof surface into daylight and energy simulations without making customized meshings, because I assumed that it might be automatically converted to meshs by Honeybee - Am I right? As showed in the image, how can I reduce the number of meshs in a proper way? Must two connected surfaces (i.e. wall and roof) be STRICTLY/SEAMLESSLY connected or not (considering different divisions of meshs in the respective surface)? - Is a connection tolerance allowed?
2) But, when I run the annual daylight simulation for this case, it gave me a lot of warnings "oconv: warning - zero area for polygon".- is that normal? and how to avoid this? Does the daylight simulation allow "curved NURBS surfaces"?
3) Moreover, when I run an energy simulation for this case, it costed extremely long time. It was just so long that I did not even have results out of one simulation. - I guessed it might be the problem caused by the curved roof surface (or automatic meshing?), but I don't have experience of converting a curved NURBS/spheral surface into correct meshs that can be recognized by Honeybee simulations (Daylight and Energy) in a proper way.
4) The large window on the wall was generated by the "_glzRatio". But the automatically generated wall meshs around this window are just too "fine", which might largely increase simulation time. Is there a proper way to get rid of it? (Considering that the size, shape and position of the window will have large influence on the daylight distribution in the building, it is worthy to keep the size, shape and position of the window as it should be in reality).
In sum, considering all above, could your please provide me some suggestions/tutorials/links that might be helpful for dealing with "curved NURBS surfaces" in Honeybee simulations.
Thank you all in advance!
Best,
Ding
…
ing the maps to the broader community.
At the moment, there are just a few known issues left that I have to fix for complex geometric cases but they should run smoothly for most energy models that you generate with Honeybee. Within the next month, I will be clearing up these last issues and, by the end of the month, there will be an updated youtube tutorial playlist on the comfort tools and how to use them.
In the meantime, there's an updated example file (http://hydrashare.github.io/hydra/viewer?owner=chriswmackey&fork=hydra_2&id=Indoor_Microclimate_Map) and I wanted to get you all excited with some images and animations coming out of the design part of my thesis. I also wanted to post some documentation of all of the previous research that has made these climate maps possible and give out some much deserved thanks. To begin, this image gives you a sense of how the thermal maps are made by integrating several streams of data for EnergyPlus:
(https://drive.google.com/file/d/0Bz2PwDvkjovJaTMtWDRHMExvLUk/view?usp=sharing)
To get you excited, this youtube playlist has a whole bunch of time-lapse thermal animations that a lot of you should enjoy:
https://www.youtube.com/playlist?list=PLruLh1AdY-Sj3ehUTSfKa1IHPSiuJU52A
To give a brief summary of what you are looking at in the playlist, there are two proposed designs for completely passive co-habitation spaces in New York and Los Angeles.
These diagrams explain the Los Angeles design:
(https://drive.google.com/file/d/0Bz2PwDvkjovJM0JkM0tLZ1kxUmc/view?usp=sharing)
And this video gives you and idea of how it thermally performs:
These diagrams explain the New York design:
(https://drive.google.com/file/d/0Bz2PwDvkjovJS1BZVVZiTWF4MXM/view?usp=sharing)
And this video shows you the thermal performance:
Now to credit all of the awesome people that have made the creation of these thermal maps possible:
1) As any HB user knows, the open source engines and libraries under the hood of HB are EnergyPlus and OpenStudio and the incredible thermal richness of these maps would not have been possible without these DoE teams creating such a robust modeler so a big credit is definitely due to them.
2) Many of the initial ideas for these thermal maps come from an MIT Masters thesis that was completed a few years ago by Amanda Webb called "cMap". Even though these cMaps were only taking into account surface temperature from E+, it was the viewing of her radiant temperature maps that initially touched-off the series of events that led to my thesis so a great credit is due to her. You can find her thesis here (http://dspace.mit.edu/handle/1721.1/72870).
3) Since the thesis of A. Webb, there were two key developments that made the high resolution of the current maps believable as a good approximation of the actual thermal environment of a building. The first is a PhD thesis by Alejandra Menchaca (also conducted here at MIT) that developed a computationally fast way of estimating sub-zone air temperature stratification. The method, which works simply by weighing the heat gain in a room against the incoming airflow was validated by many CFD simulations over the course of Alejandra's thesis. You can find here final thesis document here (http://dspace.mit.edu/handle/1721.1/74907).
4) The other main development since the A. Webb thesis that made the radiant map much more accurate is a fast means of estimating the radiant temperature increase felt by an occupant sitting in the sun. This method was developed by some awesome scientists at the UC Berkeley Center for the Built Environment (CBE) Including Tyler Hoyt, who has been particularly helpful to me by supporting the CBE's Github page. The original paper on this fast means of estimating the solar temperature delta can be found here (http://escholarship.org/uc/item/89m1h2dg) although they should have an official publication in a journal soon.
5) The ASHRAE comfort models under the hood of LB+HB all are derived from the javascript of the CBE comfort tool (http://smap.cbe.berkeley.edu/comforttool). A huge chunk of credit definitely goes to this group and I encourage any other researchers who are getting deep into comfort to check the code resources on their github page (https://github.com/CenterForTheBuiltEnvironment/comfort_tool).
6) And, last but not least, a huge share of credit is due to Mostapha and all members of the LB+HB community. It is because of resources and help that Mostapha initially gave me that I learned how to code in the first place and the knowledge of a community that would use the things that I developed was, by fa,r the biggest motivation throughout this thesis and all of my LB efforts.
Thank you all and stay awesome,
-Chris…
t. So here we go!
1. Honeybee is brown and not yellow [stupid!]...
As you probably remember Honeybee logo was initially yellow because of my ignorance about Honeybees. With the help of our Honeybee expert, Michalina, now the color is corrected. I promised her to update everyone about this. Below are photos of her working on the honeybee logo and the results of her study.
If you think I'm exaggerating by calling her a honeybee expert you better watch this video:
Thank you Michalina for the great work! :). I corrected the colors. No yellow anymore. The only yellow arrows represent sun rays and not the honeybee!
2. Yellow or brown, W[here]TH Honeybee is?
I know. It has been a long time after I posted the initial video and it is not fun at all to wait for a long time. Here is the good news. If you are following the Facebook page you probably now that the Daylighting components are almost ready.
Couple of friends from Grasshopper community and RADIANCE community has been helping me with testing/debugging the components. I still think/hope to release the daylighting components at some point in January before Ladybug gets one year old.
There have been multiple changes. I finally feel that the current version of Honeybee is simple enough for non-expert users to start running initial studies and flexible enough for advanced users to run advanced studies. I will post a video soon and walk you through different components.
I think I still need more time to modify the energy simulation components so they are not going to be part of the next release. Unfortunately, there are so many ways to set up and run a wrong energy simulation and I really don’t want to add one new GIGO app to the world of simulation. We already have enough of that. Moreover I’m still not quite happy with the workflow. Please bear with me for few more months and then we can all celebrate!
I recently tested the idea of connecting Grasshopper to OpenStudio by using OpenStudio API successfully. If nothing else, I really want to release the EnergyPlus components so I can concentrate on Grasshopper > OpenStudio development which I personally think is the best approach.
3. What about wind analysis?
I have been asked multiple times that if Ladybug will have a component for wind study. The short answer is YES! I have been working with EFRI-PULSE project during the last year to develop a free and open source web-based CFD simulation platform for outdoor analysis.
We had a very good progress so far and our rockstar Stefan recently presented the results of the work at the American Physical Society’s 66th annual DFD meeting and the results looks pretty convincing in comparison to measured data. Here is an image from the presentation. All the credits go to Stefan Gracik and EFRI-PULSE project.
The project will go live at some point next year and after that I will release the Butterfly which will let you prepare the model for the CFD simulation and send it to EFRI-PULSE project. I haven’t tried to run the simulations locally yet but I’m considering that as a further development. Here is how the component and the logo looks like right now.
4. Teaching resources
It has been almost 11 months from the first public release of Ladybug. I know that I didn't do a good job in providing enough tutorials/teaching materials and I know that I won’t be able to put something comprehensive together soon.
Fortunately, ladybug has been flying in multiple schools during the last year. Several design, engineering and consultant firms are using it and it has been thought in several workshops. As I checked with multiple of you, almost everyone told me that they will be happy to share their teaching materials; hence I started the teaching resources page. Please share your materials on the page. They can be in any format and any language. Thanks in advance!
I hope you enjoyed/are enjoying/will enjoy the longest night of the year. Happy Yalda!
Cheers,
-Mostapha
…
ger work.
Be aware, this release breaks file-forwards compatibility. You will not be able to open gh and ghx files saved with 0.8.0050 on previous versions, though of course you should be able to open old files without problems. If this is not the case, please yell loudly.
If you're having trouble loading Grasshopper, note that you must have the latest Microsoft C++ Runtimes installed on your machine. They can be downloaded from the microsoft website.
The new release can be downloaded from the usual location.
Here's a list of changes, additions and fixes since 0.8.0013:
File format forwards compatibility has been broken. You will not be able to open files saved with 0.8.0050 on earlier versions.
This release contains many breaking changes and GHA libraries compiled for older version may not work anymore.
Grasshopper Binary files (*.gh) are now saved as compressed data.
Grasshopper Binary files (*.gh) are now the default format.
Support for ancient versions of the Text Panel (still called Post-It from back then) has been removed.
Support for ancient versions of the Path Mapper (still called Path Lexer from back then) has been removed.
Placeholders for ancient versions of the Graph Mapper have been removed.
Gradient input parameters now show state tag icons (Reversed, Flatten etc.).
Geometry Cache name changes are now updated on every key press.
Geometry Cache name changes can now be cancelled with Escape.
Geometry Cache name changes can now be undone.
Mesh|Mesh intersection component now uses a different algorithm. The old behaviour is still available from the component menu.
Warning and Error balloons are now drawn as part of a Canvas Widget and will no longer show up in the Hi-Res image export.
Galapagos now accepts multiple fitness values. The true fitness will be the average of the collection.
Galapagos wires are drawn much fainter when the Galapagos object is unselected.
Medium fast redraw mode in Galapagos now immediately redraws instead of at the end of each generation.
Redesigned all Grasshopper file format icons and added larger size icons for high-dpi explorer views.
Redesigned the Most Recently Used files menu, it should now display much quicker.
Compass widget has been rewritten in an attempt to increase display performance.
Added preferences section for Compass widget.
Added preferences section for Align widget.
Added preferences section for Default Preview colours.
Added preferences section for Document Preview colours.
Added preferences section for the Most Recently Used files menu.
The Area component now accepts Breps, Meshes and Planar Closed Curves.
The Area Centroid component now accepts Breps, Meshes and Planar Closed Curves.
The Volume component now accepts Breps and Meshes.
The Volume Centroid component now accepts Breps and Meshes.
Added Merge Faces component (Surface.Util panel).
Added a Mesh Smooth component (Mesh.Util panel).
Added a Curve Seam component (Curve.Util panel).
Added Interpolate Curve With Tangents component (Curve.Spline dropdown).
Added GrasshopperFolders command to open Settings, Components and UserObject folders without loading the core plugin.
The window that reports on certain Loading Errors now has a Copy button.
Added Simplify post-process filter to parameters (in addition to Reverse, Flatten and Graft).
Parameter post processes (Reverse, Flatten, Graft & Simplify) can now also be assigned to output parameters.
Version History window now has formatting (not happy with this, I'm working on something better).
The Process Info window is gone.
Main menu has been redesigned.
Canvas toolbar has been redesigned.
Canvas context menu has been replaced by a Radial Menu.
Canvas now has a radial menu which will pop up on Middle Mouse Button clicks.
It's possible to switch between Radial and Legacy menus in the Preferences (Interface.Canvas section).
'Save As Copy' feature has been replaced by 'Save Backup' which is a GUI-less save including date+time stamp.
Added a 'Show in Folder' item to the File menu.
AutoSave settings are no longer available from the File menu, you now need to use the Preferences.
Selection shifts now also modify the view so you can use Ctrl+Left and Ctrl+Right to navigate up and downstream.
Mesh Edge display can now be toggled with Ctrl+M.
Preview modes now have shortcuts (Ctrl+1 = no preview, Ctrl+2 = wireframe, Ctrl+3 = shaded).
Solution States now have a default name.
Data Viewer window now responds to all required events.
Data Viewer window can now handle input and output parameters as well.
Canvas Navigation pane can now be dragged using the icon in the upper left corner.
The Persistent Data Editor has been redesigned.
It's now possible to select multiple items in the Persistent Data Editor list and edit their properties.
It's now possible to drag multiple items at the same time in the Persistent Data Editor list.
Item addition to the Persistent Data Editor is much improved.
The Persistent Data Editor is now non-modal.
The Canvas would remain black upon maximizing the Rhino window, this is fixed.
Sliders would cause multiple updates under certain conditions, this is fixed.
Digit Scrollers would cause multiple updates under certain conditions, this is fixed.
Pipes were inside out. This is fixed.
The curve component would not adjust invalid nurbs degrees, this is fixed.
Curves referencing Brep edges failed to load, this is fixed.
Points referencing Brep edges failed to load, this is fixed.
Referenced dlls in the VB/C# components sometimes resulted in invalid imports statements, this is fixed.
Pasting geometry in Rhino would cause a recompute of the Grasshopper solution, this is fixed.
Importing a file into the Rhino document would cause a recompute of the Grasshopper solution, this is fixed.
Galapagos would trigger superfluous solutions, this is fixed.
Mesh Solid Difference had a wrong name and description, this is fixed.
Several menu items were not greyed out despite not being usable, this is fixed.
The position and size of the Grasshopper window failed to get stored on Rhino shutdown, this is fixed.
The Persistent Data Editor would crash on parameters that did not support data proxies, this is fixed.
I'll add some additional information regarding some of the new UI features in subsequent posts.
--
David Rutten
david@mcneel.com
Poprad, Slovakia…
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.
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