Horticulture and Landscape in same time.
The most common plastic materials used as agricultural films are the low density polyethylene (LDPE, with a density less than 0.93 kg m−3), the copolymer of ethylene and vinyl-acetate (EVA)
Also here you can find the characteristics of the flexible materials for greenhouse covers (adapted from CPA, 1992 and Tesi, 2001) as much as i get.
UV-PE Film ( UV-PE~ polyethylene Long life or UV)
Thickness (mm) = 0.18
Direct PAR transmissivity (%) = 90
Diffuse PAR transmissivity (%)= 86
Long-wave IR transmissivity (%)= 65
EVA Film ( EVA~Ethylene vinyl-acetate copolymer)
Thickness (mm) = 0.18
Direct PAR transmissivity (%) = 90
Diffuse PAR transmissivity (%)= 76
Long-wave IR transmissivity (%)= 27
and here you will find the global heat transfer coefficient’ (K in W m−2 °C−1) for the above greenhouse covering materials, measured under normalized conditions (temperatures: exterior: −10°C, interior: +20°C, wind: 4 m s−1). (Source: Nisen and Deltour, 1986.)
Cover Clear sky Overcast Sky
Single PE 8.8-9.0 7.1- 7.2
Single EVA 7.8 6.6
Note : the PAR radiation (photosynthetically active or photoactive radiation and its the amounts to 45–50% of the global radiation; Berninger, 1989)
The name PAR is used to designate the radiation with wavelengths useful for plant photosynthesis. It is accepted that the PAR radiation ranges from 400 to 700 nm (McCree, 1972), although some authors consider the PAR from 350 to 850 nm.
The composition of the radiation changes with time, as a function of the Sun’s elevation and the cloudiness. When the Sun is low over the horizon, the short wavelengths are reduced (less UV and more red). The clouds reduce the amount of energy, greatly decreasing the NIR.
The PAR proportion in relation to the global radiation increases with scattering (diffusion). It is lower with clear sky and in the summer (45–48%).
kind regards
rafat …
Grasshopper. So, I once made an attempt to bind ms sqlServer in order to get frozen definitions at some states, to avoid managing baked objects in Rhino and also be able to retain whole results without using the GH state manager that rebuilds everything.
But at that time GH's VB.Net component didn't properly read referenced dlls and I forgot it since then.
At first, I was surprised by Slingshot's extensive interface : I was still having in mind my own old project, a tool that would have acted at the Rhino's geometry object level, and auto creating the needed tables.
The bd would have consisted of a main table, owning the objects ID and name, and related tables containing the necessary information relative to the main objects.
For example, a Brep is made of so and so underlying objects, passed to respective tables, according to GH objects definition layout (just the way they are written in the xml schema).
Then, on a db, query an object by name, and retrieve the whole object or underlying objects (e.g. at the bounding curves level, or points level for a Brep).
With Slingshot, I made a few attempts to cheat GH with BLOB data fields, but no way to get a whole object. It seems that GH simply provides an object.toString ... and GH is definitely not conceived to produce persistence outside of Rhino. If I have some spare time, I will try to extract
About points and colors, I am now simply using a single field with CHAR(asLargeAsNeeded...), as GH parses String to every Point (or Vector or Color) entry of any component.
I do so because it need less to display on the canvas...
Whatever I wrote before, I really like your conception, as opened to relational interactions between ...whatever you need or dream of !
One last thing : GH can't open the definition file "Genome_DB_Template.gh" that I've downloaded from your site : http://slingshot-dev.wikidot.com/database-genome. I was expecting to learn a lot from your very smart stuff ! (I am running GH 08.00.13 and Slingshot 0.7.2.0)
Slingshot is running great, opened to any use...Thanks again.
Best,
Stan
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Refinement component at first, possibly using MeshMachine instead which is slow but actually gives many fewer triangles and adaptive meshing for tight curves too. Neither are easy to adjust on a deadline!
Then you have to sneak up on workable settings, using only a few lines, or Grasshopper will freeze perhaps indefinitely for 200 lines with extreme settings, especially the CS (Cube Size) setting that can blow up into a huge number if your scale is big.
Cocoon gives lots of nearly flat split quad faces so I quadrangulated those for fun:
Or MeshMachine can refine the mesh to make it efficient:
Whereas the Cocoon Refine component will merely return an equally fine mesh with more equilateral triangles but no serious remeshing to rid so many tiny triangles where they are not needed? Actually, it does seem to remesh also:
David said he used some of Daniel's MeshMachine code in there.…
a pain to use sometimes. I recently found this great post:
http://www.grasshopper3d.com/forum/topics/formatting-numbers-in-grasshopper
which points to the msdn .net framework standard numeric format strings:
http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx
and the custom ones too:
http://msdn.microsoft.com/en-us/library/0c899ak8.aspx
Sooo... today I was trying to make a 2D array generator for RGB values to use with a RGB LED and an Arduino. For instance, declaring a 2D array in Arduino:
int color[3][3]={{255,0,0},{0,255,0},{0,0,255}};
I'm using the blend color component to spit out transitions between two colors. I want the list in the panel to be in the format above, so I used both the expression component and the string format component (are they the same under the hood?). In any case, if I have R, G and B values coming into the component, I want to format them so the come out looking like {R,G,B}, so I can just copy the output in a panel and paste it into the Arduino IDE. But what about {curly braces}. If the expression/format component uses them in it's syntax, for instance:
Format ("{R:0},{G:0},{B:0}",R,G,B)
how do I get them into the formatting string? I tried escaping them like:
Format ("\{{R:0},{G:0},{B:0}\}",R,G,B)
but that just makes the component angry
Escaping characters is explained in the formatting references above. Is it implemented in this component? Should I be looking at a different approach?
I've included a sample file below.
Thanks!
~BB~
…
ing-in-python?commentId=2985220%3AComment%3A628495
For the most part, I got the serial port to work and I could share the port with other components without wiring the components together using a sticky Python dictionary. There were a couple of issues with closing the port (Rhino had to be restarted).
In any case, I'm back at it. I am however going the C# component route with an eye towards writing my own components with visual studio. I am trying to create bidirectional communication with a serial device in grasshopper. I need more control over the serial port that the generic Firefly components can afford. Furthermore, I would like to understand how to program this myself. The first goal would be to create a few components that could handle various serial tasks, one to open/close port, one to read from port and one to write to it. This is not unlike how I got it to work in python, and is also similar to the logic in Firefly's serial components.
The thing that has me stumped with C# is how one shares the port between components? If one component is responsible for creating and opening/closing the port, how do the read/write components address the instance of the port created in the other component? Python has the sticky dictionary, is there something similar in C#? I'm a novice when it comes to C# and how it works within grasshopper, so maybe I'm missing something simple.
I've attached a klunky definition that uses C# to open/close a serial port. I've tried accessing the port with other components, but I don't know enough to make it work. Again, I'm mainly interested in the mechanics of how one component can access the serial port instance created in another component. If I could get some user objects going for now, I'd be happy. In the future, I want to roll my own components. If anyone has any suggestions, code snippets, or any other forms of enlightenment, I'd be greatly appreciative!
Rhino5 x64 + GH version 0.9.0056
Thanks,
~BB~
…
ace Syntax." eCAADe 2013 18 (2013): 357.
http://www.sss9.or.kr/paperpdf/mmd/sss9_2013_ref048_p.pdf
The measure Entropy is newer. I hereby explain it (from my PhD dissertation):
Entropy values, as described in (Hillier & Hanson, The Social Logic of Space, 1984) and specified in (Turner A. , “Depthmap: A Program to Perform Visibility Graph Analysis, 2007), intuitively describe the difficulty of getting to other spaces from a certain space. In other words, the higher the entropy value, the more difficult it is to reach other spaces from that space and vice-versa. We compute the spatial entropy of the node as using the point depth set:
(11)
“The term is the maximum depth from vertex and is the frequency of point depth *d* from the vertex” (ibid). Technically, we compute it using the function below, which itself uses some outputs and by-products from previous calculations:
Algorithm 4: Entropy Computation
Given the graph (adjacency lists), Depths as List of List of integer, DepthMap as Dictionary of integer
Initialize Entropies as List(double)
For node as integer in range [0, |V|)
integer How_Many_of_D=0
double S_node=0
For depth as integer in range [1, Depths[node].Max()]
How_Many_of_D=DepthMap.Branch[(node,depth)].Count
double frequency= How_Many_of_D/|V|
S_node = S_node - frequency * Math.Log(frequency, 2)
Next
Entropies [node] = S_node
Next
…
starting as soon as possible.
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Our ideal candidate:
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We're looking forward to your applications / inquiries / CVs to: mpelzer@fat-lab.de
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…
hen you determine their position and number by the "precision_" input. Their number is equal to "precision_ - 1".They are essentially mesh edges, not curves. To hide them, in Rhino application menu choose: Tools -> Options -> View -> Display Modes -> choose your current display mode, and uncheck the "Show mesh wires":
b) How do you change the x- and y-scale of the chart? For instance displaying every 10 degrees of azimuth?
Can you be a bit more precise?You would like to change the labeling of the azimuth directions from 30 degrees step to 10 degrees step? If this is so, you can not do that.
c) My input surface is a hyperbolic paraboloid, facing south symmetrically. How does the component calculate its tilt and azimuth?
All Ladybug Photovoltaics components calculate the amount of AC energy generated by a planar (flat) surface. Tilt and azimuth angles are calculated based on surface normal at 0.5, 0.5 surface parameters. So you can not use the hyperbolic paraboloid as the _PVsurface (or _PV_SWHsurface) input, as it will yield incorrect results. You need to planarize that hyperbolic paraboloid surface first.I attached below an example with default grasshopper components, but the size of the panels is not equal. If you want them to be equal use some paneling Grasshopper plugin like Lunchbox or Paneling tools.…
hreads where Thread I solves object A1 and Thread II solves object A2. As soon as A1 is completed, Thread I can move on to object B1 and as soon as A2 completes, Thread II can move on to object B3 (whichever comes first). When both A1 and A2 are complete, we can spawn a new thread (III) to take care of object B2.
If B2 completes before B3, then Thread III will terminate. If B3 completes before B2, then Thread II terminates. Whichever thread is last will pick up execution of object C3. And so on and so forth.
This sort of threading is actually not guaranteed to help much though, as it is likely that the bottleneck components in the network will still need to be handled by a single thread.
A more efficient solution would be to divvy up the execution per component to multiple threads. If you're trying to compute the Curve Closest Point for 10,000 points and your machine contains 4 cores, then we can assign 2,500 points to the first core, 2,500 points to the second core etc.
This approach will actually work when there's only a few bottleneck components and it also means the order in which components are solved is no longer important.
An even more fine-grained approach to threading would be to make the Curve Closest Point function in the Rhino SDK threaded. There's a lot of looping going on in any given Curve CP computation so the curve could be broken up into loose spans where each span is solved by a different core. Then the partial results get consolidated once all threads finish.
The benefit here is that it would be multi-core for everyone, not just Grasshopper components.
The bad news: Some functions in Rhino are not thread-safe. Meaning that data structures such as NurbsCurves cannot be modified from multiple threads at once as it will compromise their validity. You might well end up with invalid curves and quite possible weird crashes. In very bad cases it might even be that a specific function in our SDK can only be running once, so even if you were to duplicate the curve it would still not work.
Until our SDK is thread-safe there can be no global threading in Grasshopper. I don't know where we're headed with this, but I do know that we've started using some threaded algorithms in the display as of Rhino5, so it seems we're at least getting our feet wet.
--
David Rutten
david@mcneel.com
Seattle, WA…
Added by David Rutten at 5:47pm on November 17, 2010
r "virtual partitions" as follows:
What I mean "air walls" here, is derived from the description of the E+ documentation with the header of "Air wall, Open air connection between zones". (Page 17, http://apps1.eere.energy.gov/buildings/energyplus/pdfs/tips_and_tricks_using_energyplus.pdf)
As I understand, the term "air wall" used in E+ here refers to a description of something like "boundary condition" between adjacent interzone heat transfer surfaces, but not a kind of "construction or material" (like air space resistance or air gaps within a wall/double glazing window).
The main purpose of introducing the "air wall", is to simulate or approximate the airflow/convection/natural ventilation effect between multiple thermal zones which are connected by a large opening.
In my previous tests, using HBzones and GB, I managed to create the gbXML file which can be successfully imported to DB (without assigning any constructions within HB). And the adjacency condition can be recognized automatically by DB, even when I did not use the "Solve adjacencies" component in HB - shared surfaces between multiple thermal zones are recognized automatically by BD as "internal - partition"(which are standard partitions, but not virtual partitions).
In order to create/approximate "virtual partition", I need to manually draw a "hole" in the standard partition surface (fig.1&2). Again, the reason why we want to use "virtual partitions"(or "air wall") is that it allows airflow between multiple thermal zones which are connected by large openings and we could get different temperature of the each subdivided thermal zone which compose a large thermal zone.
My question is, if there is a possible way to simulate/approximate this kind of "virtual partitions"(or "air wall") in HBzones or in GB? If so, I would like to test if DB recognizes it or not. Actually, we expect that there is no need to involve any manual operations (like drawing a "hole" in the standard partition surface) in DB, due to an automatic optimization loop.
Thank you!
Best,
Ding
fig.1
fig.2
…