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Josh Leverette's picture

Filters

I have spent quite a number of hours tonight reading a couple of different chapters from this book (source here), and it has turned out to be an excellent resource. I learn best through visualization; I reason better with an abstract concept after I've seen visualizations of it, whereas most teachers I've ever had prefer to start with the mathematical notation first, which is purely abstract. Thus, the discovery of this IPython / Jupyter book about filters is deeply intriguing to me. It combines the abstract with the visual, not to mention some demonstrative code, and I am therefore enjoying it quite a bit.

Particle filters are interesting. I'm starting to see why they would take less tuning than a traditional Kalman filter, but at the same time I can also see why they would be more computationally intensive. Some of the discussion in this book seems to touch on why a Kalman filter might not be the optimal choice for a dead reckoning system. I believe this book is a great resource for anyone who wants to learn more about these types of filters.

EDIT: and why does this Drupal page seem to grow in unreliability with each passing day? I'm on a full, desktop version of Chrome right now and the Preview / Save buttons are completely dropping my blog post. I will keep submitting it occasionally until the server decides to start cooperating. Maybe someone is doing maintenance on the server? No idea, but it's weird behavior. (At least 10 minutes of trying to submit now)

Researching WebLogo hosting

Alongside reviewing the API documentation, I've started researching github as a possible host for the WebLogo project. My previous experiments with Heroku didn't work, and it may be possible to use the github pages features. The quickstart makes it seem easy, but running .cgi files makes the process more complicated. I still need to make an appointment with AWS to review that possibility of moving the WebLogo service from Rackspace.

MDN 7/29/2015

My code was not handling the case of no diagrams in the site properly. I edited some code to facilitate that. In the testing I did I found out that when a full screen is used for a single diagram it does not work well for all diagrams. I am working on fixing that. CSS is art but sometimes it just drives me crazy!! I will also add a zooming and panning feature using a jQuery library I found before.

Josh Leverette's picture

Particle filters

I began looking at particle filters, and while I learned some interesting things about them, such as that they are more computationally intensive than Kalman filters, I admit that I didn't spend quite as much time on task today as I had planned.

Reviewing API

I started reading the WebLogo API docs and noting questions that I have for the main author regarding updates to it.

2015-07-29

  • Created GRPC page on the Mumble.info wiki. The page currently contains the getting started guide that walks through a sample application.
  • Posted in the grpc pull request that the library is ready for testing.

Tomorrow: write some documentation that was missed; look at wish list for extra features that could be added.

29 July - Noseyparker

I added PII detection logic to my TLS proxy connection handler - so far I'm parsing HTTPS request query strings and headers for PII. I compared a small number of alerts against PII I found in clear-text (unencrypted) traffic logs for the same apps (traffic logs were collected using the mitmproxy tool). The alerts raised look correct and I'm more confident the handler is working properly.

Now that I'm inspecting HTTPS traffic I noticed there is a conflict with the HTTP traffic handler. It doesn't look too difficult to fix but will require some thought to get the design right.

I started a new subject this week, and need will need to do some admin and get started on the research project over the next 2 days - I still plan to do work on the SoC project just less than usual.

MDN 7/28/2015

I redesigned MDN interface and removed the layout button and added the functionality to the diagram browser. I think it is much easier now for users to choose the wanted layout (0, 1, or 2 diagrams) by selecting the desired diagrams in the diagram browser. The layout will change according to the number of selected diagrams.

Josh Leverette's picture

Continued Kalman exploration

I've found some excellent material discussing single variable Kalman filters, and I believe I have a decent grasp of the concepts. I need to find some simple examples of multivariable Kalman filters, and to start modeling my system, which seems to be notably more complex than the examples I've read.

Edit: as noted elsewhere, I'll probably be looking at Bayesian particle filters tomorrow and see how they compare in terms of complexity and effectiveness with Kalman filters. It sounds like determining the exact values for a Kalman filtering system could sink large amounts of time, potentially.

2015-07-28

  • Completed version 1 of murmur-cli (the sample application using the grpc API). It's possible that additional features will be requested later on, but I believe it's a good enough for debugging for the moment.
  • Finished the "getting started" project, although some more documentation should accompany it before release. After those docs. are written, the grpc system should be ready for user testing.

Tomorrow: complete documentation for the getting started project; notify users that the system is ready for testing.

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