Hello I have got an assignment to write a program, which will visualize a Graph, implemented in any way. I have no problem in implementing Graph, but I have no idea how can I visualize it.
The rules are:
- include graphs with vertex and edge labels, directed and non-directed;
- drawing clarity (avoiding large clusters of vertices and edges, avoiding cutting edges and breaking them in many places)
Do you have any tips or suggestions which language or tool should I use to do it, or when can I find help to deal with this type of problem, I'd be glad. I don't know how to make anything graphic, never done that. I am coding mostly in Java, Python and C++, but I am not advanced.
I am working on a similar problem. The approach I'm working with currently has been first creating a node, then animating it, and repeating for all nodes
https://dl1683.github.io/DataStructuresInJavaScript/index.html.
The Github code might be useful to you. I am not a web dev guy so be careful about doing everything I did.
Related
I would like to test my recently created algorithm on large (50+ node) graphs. Preferrably, they would specifically be challenging graphs, and known tours would exist (for at least most of them).
Problem sets for this problem do not seem as easy to find as with the TSP. I am aware of the Flinder's challenge set available at http://www.flinders.edu.au/science_engineering/csem/research/programs/flinders-hamiltonian-cycle-project/fhcpcs.cfm
However, they seem to be directed. I can probably alter my algorithm to work for directed, but it will take time and likely induce bugs. I'd prefer to know if it can work for undirected first.
Does anyone know where problem sets are available? Thank you.
quick edit:
Now I am unsure if the flinder's set is directed or not.... It doesn't say. Examples make it seem like maybe it actually is undirected.
Check this video:
https://www.youtube.com/watch?v=G1m7goLCJDY
Also check the in depth sequel to the video.
You can determine yourself how many nodes you want to add to the graph.
It does require you to construct the data yourself, which should be deable.
One note: the problem is about a path, not a cycle, but you can overcome this by connecting the start and end node.
I am studying graph databases (Neo4J).
I know graph databases come from graph theory, which has basis on Euler paper to solve the 7 bridges problem.. eulerian path/eulerian circuit.
I am trying to find an example, something, to show how graph databases use the Eulerian path to solve some problem.
Ideally I would need a real example from a source, but even any help to understand this better.. thanks!
I believe you have a misimpression. Even though Euler wrote a paper based on the 7 bridges problem (which was probably the first paper on graph theory), that does not mean that the design of neo4j uses his solution to that specific problem in any way.
I'm hoping you can help me out with some technical questions on graphs/trees.
I'm trying to display the creation of objects in systems.
It's really a tree structure.
It has some interesting requirements.
a)
One node can have many children. Say 20. Maybe more.
ie. one library can be used by many objects.
b)
A child node can have many parents. Say up to 20.
ie. many libraries are used by one procedure or object
c)
A particular node can appear in more than one place.
ie. a generic print, or logging function is called in many procedures
Note: This is just an -example- in tech terms I expect you will understand.
It is NOT the issue I need to model. No need to discuss it.
As I've thought about it, I realized that it's not a simple binary tree, or a linked list.
1)
What kind of data structure could I save all the data in?
2)
How could I produce a graph of this in java?
3)
What is a free open source graphing software that could graph such a tree?
Such as Neo4j
Perhaps in formats:
- as a tree, with a root, trunk, branches, and leaves?
- Like the graphs you see now, depicting social networks, with the root node in the center?
4)
Any good websites, or tutorials on this subject?
Thanks a lot!
Check out prefuse. It's old but it works. You'll have to invest a bit of time to learn how to use it though. Once you get there, it's just a matter of creating a prefuse.data.Graph object and fill in your nodes and their neighbors and then creating the visualization.
If you're open to other solution check out d3.js - draw graph using javascript on SVG element in your browser.
If this is really about objects, then maybe UML can help. It's designed to generate graphs of object relationships. There are tons of free UML tools out there. I'd download one and see if you can shoehorn your application into it.
JGraphT can represent your graph structure and can use JGraph for visualisation.
For an example visualization, look at this.
I have a client who is based in the field of mathematics. We are developing, amongst other things, a website. I like to create a mock-up of a drawing tool that can produce some imagery in the background based on some scientific algorithms. The intention being that the client, later, may create their own. (They use emacs for everything, great client.)
I'm looking for an answer about where or what to search. Not code specific, pseudocode even, as we can adapt and have not yet settled on a platform.
I'm afraid my mathematics stops at the power of two and some trigonometry. Appreciated if they're are any mathematics related students/academics how could enlighten me? What to search for will be accepted?
Edit: To summarise/clarify, I want to draw pretty pictures (the design perspective). I want them to have some context (i.e. not just for the sake of pretty images but have some explanation available). In essence I would to create a rendering engine which they can draw/code the images and we set the style parameters: line, colour, etc... But to pursue this option I want to experiment myself.
Edit: great responses thanks. The aim is to make something along the lines of http://hascanvas.com/ if anyone is interested.
Thanks
Ross
Mandelbrot set, Julia sets, random graphs, Lorenz attractor.
Maybe minimising energy functions on a sphere.
I'm quite sure that I don't fully understand what you are after, so to provoke you and others into clarifying, I suggest you grab a copy of Mathematica and of Web Mathematica and knock your clients out with that.
Mandelbulb.
Fractals with pseudo code.
You can have a look at these links:
https://mathshistory.st-andrews.ac.uk/Curves/
https://www.nctm.org/classroomresources/
https://planetmath.org/famouscurves
In working on a shortest path algorithm across a network I would like to generate a picture of the network. I'd like to represent nodes (circles), links (lines), cost to traverse the link (number in the middle of the link line), and capacity of the link (number on the link line next to the node it represents) in the picture. Is there any library/software out there that would help to automate creating this picture?
I can do this manually in Visio or with some drawing application but I'd like to generate them from code as I change/tweak the network.
Sounds like a job for GraphViz , it generates graphs from a short text description file. I've used it to produce connected node graphs and I believe it should be possible to add link labels, as you require.
If you're using python, Nodebox draws pretty graphs.
One of the big problems in displaying networks like this is figuring out where to put the nodes on the display screen. If arranging nodes is logically simple given your network, then an off-the-shelf product is likely to suit your needs.
If the arrangements are much more complicated, you may have to accept a certain amount of manual intervention to get this to work with off-the-shelf stuff, or byte the bullet and program the whole thing yourself.
.NET is one choice, and once you've mastered the Graphics class it's easy to use and plenty fast for something like this. However, there are probably better languages/platforms than .NET for something graphics-oriented like this.
Update: .NET is much better for 2D graphics than I knew. The key is finding a fast workaround to the pitifully slow GetPixel() and SetPixel() methods in the Bitmap class. Once you can read and write individual pixels easily and quickly, you can do whatever you want as a programmer.
Did you by chance check out the R programming language? I'm not positive but I believe that you can make images and such out of graphs. r-project.org
There are a bunch of visualizations of various algorithms here: Algorithmics Animation Workshop