graphic: domain-specific language to describe the tree path (assembly model)

I'm looking for some widely used tool / library / approach to describe the hierarchical model structure as a set:
hierarchical model example

It is absolutely simple how to do it with a simple set like
simple set

It can even be explained in yml format like this:

code: "cats"
  - code: "siamese"
  - code: "persian"
  - code: "sphynx"

It is obvious from the code that runs a simple set model that lets go first and the parent model adds its results.

But it seems difficult to describe the hierarchical model in the same way because it runs in the reverse direction. Probably someone can suggest an approach to do it.

Android: how to organize graphic and touch code? (between GLSurfaceView and Renderer)

I just need the camera shake, and I have something working, but it's an ugly trick. What is the correct way to do it? The organization of the code or "architecture".

What I have noticed:

  • GLSurfaceView get onTouch callbacks; but Renderer have access to GL.

  • Shaders and textures can only be loaded after onSurfaceCreated() callback, so it should be charged there?

  • The touch and graphics are on different threads, so you should use queueEvent() or similar.

The tutorials don't seem to cover this.

Maybe some open source game is a good example of how to do it? Thanks for any help!

combinatorial – Existence of graphic keys

Strictly speaking, it is possible to build $ 2k $ keys but, under some assumptions (see below), their size will never be asymptotically better than the size of the best $ 2k-1 $ key.

In fact, assuming that the Erdős Circumference Conjecture, there are graphs $ G = (V, E) $ with circumference (shortest cycle length) $ 2k + $ 2 Y $ Omega (n ^ {1+ frac {1} {k}}) $ edges

A $ 2k $ key $ S $ from $ G $ cannot exclude any advantage $ (u, v) in E $. Actually yes $ (u, v) in E setminus S $, either $ u $ Y $ v $ are disconnected in $ (V, S) $or its distance in $ (V, S) $ At least $ 2k + $ 1. This is a contradiction.

This means that any $ 2k $ key of $ G $ must have at least $ Omega (n ^ {1+ frac {1} {k}}) $ edges however $ O (n ^ {1+ frac {1} {k}}) $ the edges are already enough to guarantee the existence of $ 2k-1 $ keys on any graph, as you point out.

scroll: display a large graphic inside a card on a Dashboard

I'm going to design a Dashboard, I know how to display the information, but my client told me that a cohort graph will have a lot of information. I am wondering if it is okay to add an arrow to the card containing the graph to expand the graph on another page and add a link to return to the board or what is the best way to do it (when we need to show more information for each card). Thank you!

manipulate: interactive graphic construction

I am interested in building an interactive GUI graphics generator, where I can add and remove vertices and edges.

I am aware of this question, and this is nothing more than a quick follow-up to this answer. I would like to simply edit the István Zachar code to answer the following questions

  1. Is it possible to recover / paste the constructed chart? How is it done (an undirected graph would be fine)?
  2. Also, I am wondering if it is possible, given a graph, to edit it with a GUI construct.

I feel like it should be relatively easy to do it using this code, but I still don't feel very comfortable working DynamicModule. I wonder if there is a Manipulate version of this.

Any ideas?

Total behavior of the graphic spectrum

Leave $ mathcal {G} $ be the set of all finite simple graphs minus complete graphs. For any $ G in mathcal {G} $, leave $ lambda _ { geq0} (G) $ denotes the smallest positive adjacency eigenvalue of the graph $ G $.

Leave $$ tau _ { mathcal {G}} = sum_ {G in mathcal {G}} { lambda _ { geq 0} (G)}. $$

It is true that $ tau _ { mathcal {G}} $ Is finite?

How to exclude a graphic object for automatic plot range calculation

In GraphicsI would like the PlotRange it will be calculated automatically, but I would like to exclude some graphic objects (in my case: auxiliary circles) from that PlotRange calculation.

How can that be accomplished?

Germany – Coronavirus graphic day by day?

Do you know any website where I can check how many cases of CoVid2020 Italy had 10 days ago?

Let me explain: we are traveling to the Dominican Republic at the end of this month with transfer to Germany (Frankfurt). At the beginning of this week, my country (Slovakia) banned all flights to and from Italy.
Therefore, I would like to check how many cases Italy had about 10 days ago, to perhaps predict future cases in Germany (possibility that all flights to Germany are also prohibited). ATM, our travel agency does not want to cancel our trip, neither do we, because we would lose our 80% of our money.

PS: Sorry for my bad English.