Standard R graphics are not particularly convenient for interactive zooming into large data sets. There's been some work with Qt for a new device, but I haven't seen a fully working example yet (pointers appreciated if I missed something).
That's how I came across Acinonyx; it is already at a usable stage, at least on OSX, and promises fast and interactive display.
Sadly, I cannot find examples to perform the following tasks:
zoom in and out with mouse interaction
display the coordinates of a selected point
I'm pretty sure both are possible / implemented, but the documentation is quite weak at the moment.
Edit: after playing around and going through iplot's documentation, it seems that the command and ctrl keys do what I wanted.
More generally, though, is there a possibility to extend the interactivity of Acinonyx with custom buttons? When hovering the top-left of the plot window, buttons appear, that depend on the plot type. I would like to create a new one for scatterplots, that would let the user select a curve and shift it vertically with the mouse.
Related
I'm working on a R Shiny app that plots (with ggplot2) information about different chromosomes, and there is also an option to show all the chromosomes together.
I have a really bad performance problem, especially with the 'all' view, I looked for some caching solutions, but didn't really find anything helpful.
I thought to put 2 tabs in my app, the first is for the single chromosomes, and the second for all together, so it would run in the background, and load while the user is still in the first tab, but when I read about Tabsets I found out this-
Notice that outputs that are not visible are not re-evaluated until they become visible.
So my question is, is there a way to bypass this? or is there a way to cache a plot so when I want to plot it the only thing left to do is to draw it, and skip the construct, build, and render stages. (there is a good chance that I don't really understand the plotting process, and it's not possible)
One last thing, I am aware of (the much faster) ggvis and ggobi, but these are for now not an option.
i'm working on a simple game project with libgdx and i need some help to make a random infinite world. After googling for hours i knew that many games use the "chunk theory" to generate an infinite map and also implement tiles. There are many things i don't understand... for example:
What is a tile? and a chunk?
How can i implement this "chunk theory" in a game?
Is this the best way to generate an infinite random map?
can someone answer my questions to make some clarifications in my mind?
Thanks in advance
Tile-based maps are maps, which are organized as a grid. A Tile is then a cell of this grid and objects are placed inside this Tile/cell and can't be placed between to cells. Think about Minecraft, every Block there is one Tile.
A chunk is a part of the map, containing many Tiles. It has a fixed size and is used to be able to load only part of an infinite map.
Imagine a map with a size of 1600*1600 Tiles. You won't be able to see all Tiles at once. Also you don't need to update the logic for the whole map, as it won't affect you anyway. So you split your map into little parts, so called chunks, which have a fixed size (for example 16*16).
Depending on your position, adjacent chunks are loaded and far chunks are unloaded. So if you move from south to nord, chunks in the nord are loaded, chunks in the south are unloaded.
I never implemented a chunk-system myself, so i can't tell you how to implement it, but i guess there are many tutorials out there.
This is not the way to generate infinite maps, but the way to store, load and work with huge maps. The generation is usualy done with some noise functions, but thats a different story.
Anyways i suggest you to start with something smaller and simpler. Rushing into to complex things will just discourage you.
I'm trying to build a small application for a specific problem in cartography. The workflow is like this:
in the field, use a compass and tape measure to obtain terrain data.
also in the field, sketch the plot being surveyed
using inkscape, create a vector drawing of that sketch
crunch the data to obtain the relevant information (implemented already)
put the vector and the data together (mostly warping and scaling the drawing - implemented already)
Now, I'd like to do the vectorizing, which I'm doing in inkscape now, directly in my custom application - this helps me characterize the sketch faster.
I had a look at the Inkscape and Karbon codebases, but the code responsible for the widgets that draw curves and paths, along with the whole user interaction parts, is quite involved. I'd like to stick to number crunching and make sure that works properly.
In short, I'm looking for something like Qwt (whichs provides plotting utilities), but directed to adding vector drawing/sketching functionality to an application. Then it'd be a matter of putting the GUI pieces together, and i'd be free to worry about the number crunching. So far I couldn't find anything like this - Inkscape, Karbon, Libreoffice, Printdesign, Gimp, they all implement their own path, curve widgets, using the graphics primitives of their frameworks and adding all the code that shows the curve moving with the mouse, the control points, etc.
Does anyone have an idea if such a pre-made framework for higher-level graphics - that lets me forget about the GUI code - exists?
Thanks!
QGraphicsScene and QGraphicsView provide enough for you to fairly simply implement the rest of it. Do note that Qt has a rather rich set of graphics primitives that you can trivially reuse, like bezier curves, paths, etc. You need to implement the application-specific bits, but the basics are done.
Recently I explored some libraries where I can visualize graphs from Neo4j, but didn't get a clear view wich one to choose, so I have a couple thought I'd like to share.
My requirements and wishes - after search throught REST API with cypher query visualize graphs with all relationships, nodes. And result make interactive - able to drag/drop... opportunity to reveal other nodes/rels on click. Import nodes throught json data and be able to show quickly up to at least 400 elements.
So I more or less explored further libraries:
Three.js - mostly for 3D. (If I don't need 3D then better not to choose this one)
Arbor.js - drawing leaves up to you, mostly layout library
VivaGraphJS - easy to use, but almost no documentation :(
D3.js - Looks fine, but uses SVG
Cytoscape.js - looks fine, but I read that I can't use it with Neo4j. Is D3.js the right choice for real-time visualization of Neo4j Graph DB data why?
Processing.js - have it's own language similar to Java. I'm not so much in Java-like language (yet).
And I have a couple questions:
1) Whats your experience - benefits, weakneses of libraries?
2) I suppose I want to use canvas insted of SVG? (a lot of small elements on the screen).
3) Arbor is special library for layout, but others don't have layout algorithms or what?
I'll appreciate any opinion! :-)
I pondered a similar situation. I chose sigma.js.
1) Whats your experience - benefits, weakneses of libraries?
sigma.js is specific to graph rendering. d3 is a full on toolbox for visualization. Since I only want to draw graphs, the concise sigma.js interface was easier to work with. I think this is the video where the creator talks about how sigma.js is able to do incremental rendering and thus perform better and handle more vertices/edges smoothly.
2) I suppose I want to use canvas insted of SVG? (a lot of small
elements on the screen).
sigma.js renders to the canvas.
Here are the sigma.js examples. The "hide nodes" example shows mouse interactions. Additionaly, here is a blog post showing how one can easily integrate neo4j w/ sigma using a very minimal amount of data massaging code written in node.js. It would be easy to port this to any server language.
I don't see sigma.js in that list which you might want to take a look at as it is very useful (example)
You will have to somehow handle the rendering of the received data (i.e. go from a data structure to its visual representation) and this depends on what are you trying to show / say with that visualisation, how you want to do it and how you want it to look like.
As a starting point, i would go with D3 and Sigma.
I note that Gephi is not on your list. As a standalone visualiser/editor, its the best that I have used (you just get the neo4j plugin, and it will import the source files of the database and let you view it). Its also Open Source, so you can include it as part of a project.
Also missing from your list is the yFiles family of graph visualization libraries.
The JavaScript variant of if uses both Canvas, WebGL, and SVG. This can give very good performance and high-quality visualizations at the same time. For hair-ball-like graphs (thousands of dots and lines, but probably no text) you can use WebGL and Canvas and when you zoom in to actually make sense of the data, you can use SVG to get detailed high-quality visualizations with labels, icons, data-bound visualizations, etc. You can use both techniques in the same visualization, even at the same time, benefiting from the best of both worlds (demo).
Connecting yFiles to Neo4j is easy using the JavaScript Bolt driver.
Aiming at 400 elements in the view is a good idea. While larger graphs tend to look really nice, most of the time you won't gain a lot of insights by looking at "hair-balls". These almost artistic visualizations all look very similar and as such carry little to no information. Often you could just as well display a static image showing the first google image search hit for a "hairball graph" query :-)
In order to better support the user during exploration, filtering, grouping, nesting, and dynamic interaction should be added to the viewer application. How this can be implemented, very much depends on the business domain in the visualization, though and there are only very few generic approaches that work for generic graphs.
Disclaimer: I work for the company that creates the above mentioned visualization library. I do not represent it on SO, though.
I'm currently evaluating the possibilities to implement a navigable 3D scene which allows to render multiple 2D layers. To be a bit more precise, I would like to display multiple graphs in a 3D environment in order to pinpoint simularities and differences between those graphs. Considering the following screenshot, there would be two graphs (one black, one grey), which are equivalent - for different graphs, deviant nodes might, i.e, be highlighted in red.
I am working with Qt's Graphic View Framework and established an editable graph editor using QGraphicsScene and several QGraphicsItems, which I separately from this project.
Qt provides OpenGL support, e.g., the QGLWidget and I had a look at the provided examples. Given, that I have not worked with OpenGL (I did some work with Java3D though) I would love if some people can share their experience.
Several solutions came to my mind:
Render every QGraphicsView to a QPixmap and display them in 3D, which would make the graphs navigatable but would prohibit any picking of elements etc.
Create an equivalent 3D element for every 2D graph element and "transform" every QGraphicsView into an 3D representation. I guess this would be quite some work (espacially as I have not worked with OpenGL)
Maybe there is an easy way to "place" the QGraphicScenes, the view, or just the QGraphicsItems in a QGLWidget without many adaptions and still register the usual "mouseclickevents" etc.
For a first implementation a plain navigable "viewer" which displayes multiple graphs in different layers would sufficient. But I would like to keep it extendable in order to add, e.g., picking, in the future.
The Qt3D project provides a class called QGraphicsEmbedScene which does exactly what you are asking for.