Visualizing Algorithms (2014) | Hacker News Reader

Visualizing Algorithms (2014)

bost.ocks.org

152 pointsswsieber12 comments

Part of what the author talks about here makes me wonder about a potential application for visualizations like this (especially since I'm working on a general purpose 'structured data' visualization system).

If seeing these visualizations of algorithms can significantly speed up human understanding, how beneficial would it be for onboarding people to (e.g.) open source projects, if the codebase had its central algorithms visualized?

For instance, consider introducing someone to the Git codebase for the first time. What if the first step was allowing them to just use Git, while they could see the data comprising the working tree, index, commit tree, etc. changing as they performed various actions? After that, they could go to the code and see which parts were responsible for producing the visualization.

Or, what if library/framework/language maintainers incorporated it to teach people how to use/debug their systems. E.g. the 'state_machine' Ruby gem. How valuable would it be if users of the library could turn on a debug flag and just see their state machines being constructed and operating?

There's a video of the visualizer I'm working on running here (including another visualization of quicksort towards the end): http://symbolflux.com/projects/avd

I currently work in DNA analysis and the biggest issue I have is conveying to people just "how complicated the math is". Often even I barely have a grasp of the complications of it.

When math produces data that fundamentally challenges your understanding of what's happening under the hood, you (I) really wish there were better ways to visualize what's happening, even if only to verify that it's happening correctly.

It gets hard to do that when your dataset for a single sample is hundreds of megabytes; it becomes difficult to aggregate the visualizations across hundreds, thousands, or even hundreds of thousands, of specific samples.

I love the idea, it'd be great to have a tool like this integrated with debuggers' watch. I'd love to be able to pick some variable and then, as I step through the code, at any point be able to see the visual representation of my data. Not a thing to use everyday probably, but from time to time it'd be immensely helpful to have it.

My original motivation for building it was because I wanted exactly that:)

You may want to check out the good ol' DDD: https://www.gnu.org/software/ddd/

Older thread.

https://news.ycombinator.com/item?id=7949995

I absolutely love these articles, and was inspired to create some (not nearly as cool) of my own.

Here is what a Graph looks like - http://gun.js.org/see/graphs.gif

Here is how an Ad-Hoc Mesh Network can deduplicate broadcast storms: http://gun.js.org/see/ad-hoc-mesh-network.gif (This is also the same principle that neurons use when firing signals!)

Here is what a Radix structure looks like: http://gun.js.org/see/radix.gif

Would love to see other visualizations by other people, please add links for me!

Referenced in the top comment of the Gambler's Fallacy discussion: https://news.ycombinator.com/item?id=14805939

The Fisher-Yates shuffle has an off-by-one.

How so? It seems correct to me.

This implementation always moves the nth item, it should only do it most of the time, it could never return the starting array but needs to be able to.

This implementation NEVER moves the nth item as that is past the end of the array.

   i = Math.random() * n-- | 0;

generates a value less than n.

And

    t = array[n];
    array[n] = array[i];
    array[i] = t;

is using a decremented n.

You are being confused by the `n--` in the random selection.

Reply on news.ycombinator.com