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phkx

142 karma · joined October 26, 2020

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phkx··on Biohacking Lite (2020)
https://karpathy.github.io/2020/06/11/biohacking-lite/

please use https links

phkx··on Open source screw counting machine
The issue is that you need to built it twice, so that you can disassemble one to get the count of screws :P
phkx··on How to use a Python multiprocessing module
The models for curve fitting in my lab were using lambdas, which cannot be serialized by multiprocessing/pickle (at least that was the state about 5 years ago). The pathos.multiprocessing module [1] served as a drop-in replacement, which was able to handle lambda with its own dill serializer. Saved me quite a bit of refactoring.

[1] https://github.com/uqfoundation/pathos

phkx··on You can link an OpenPGP key to a German eID
I should add that some of the risks mentioned in that post can be mitigated by proper user behavior (use a sufficient key length, limit the lifetime of your key). But then PGP is sufficiently complex and error prone (in using it and apparently in its technical complexity), that I don’t believe that it scales to everyone and their grandma using it.
phkx··on You can link an OpenPGP key to a German eID
I recently came along this post [0], which pretty much killed PGP for me. I certainly cannot follow all technical detail in the post, but I do see that cryptography has moved on and now offers e.g. forward secrecy.

[0] https://latacora.micro.blog/2019/07/16/the-pgp-problem.html

phkx··on Let us serve you, but don't bring us down
It‘s rather per public IP, such that e.g. behind a corporate proxy you may experience rate limiting even for regular use, just because you’re sharing a few IP addresses with a large number of users. Better hope that you get an increased quota for your external IPs in that case.
phkx··on Everything you always wanted to know about mathematics (2013) [pdf]
There might be a print shop in your area which offers similar services. Or services which explicitly offer to print thesis, but they typically require a minimum number of prints.
phkx··on Nostr (“Notes and Other Stuff Transmitted by Relays”) – An Introduction
I have to ask: crypto as in crypto currency or as in actual cryptography?

I‘m left with the impression that both our descriptions of these protocols and services are in need of some more substantial backing.

phkx··on Nostr (“Notes and Other Stuff Transmitted by Relays”) – An Introduction
> Telegram Group - where development chat happens

Telegram has stuck with me as a red flag. Mostly because Signal, which emerged around the same time, apparently had the better tech and was open. Not sure whether that changed.

phkx··on Foundations of Data Science (2018) [pdf]
The parent page by one of the authors links to a version which has been typeset more recently (in 2019).

See https://www.cs.cornell.edu/jeh/

phkx··on Ask HN: What is the best source to learn Docker in 2023?
What kind of files would you like to change? Anything that comprises the environment within the container (image) is indeed changed by rebuilding the container, but not the whole - just the layers which changed. Layering in a smart way increases reuse. Also, this way you reflect versions (tags) of the environment. Configuration can be passed in via parameters.

The data you work with should be stored externally (volume, database, accessed via API, …). You don‘t keep persistent state of your workload in the container.

phkx··on How we’re approaching AI-generated writing on Medium
The formulation of their AI policy is a bit too general. "Created with AI" could apply to both, form and content. Does using a spell/grammer checker count as using AI?

My main concern is with the content, because we're more experienced with the failure modes of humans when interpreting information. I like the other approach shown in the post, which is to cite an AI as you would with any other source. Best include the prompt then, which is also the best way when citing humans. Knowing which model generated the content on what prompt would at least enable some judgement on biases etc. which are present in the response.

Looking forward to the first AI-only interview magazine.

phkx··on Whatever happened to SHA-256 support in Git
Truncating the sha256 hashes does sound like a reasonable intermediate step and should also enable interoperability (a guess from my side - if it is only about referencing objects, it probably does not matter how the keys were generated). At some point one could then transition to the full hashes and make the truncated ones an option.

I‘m wondering what tooling is heavily dependent on the length of the hashes. Potentially if you want to keep the size of the transmitted data small (at work, we once considered git as a versioned database for an IoT use case…).

phkx··on Ask HN: What Is Going on with Neo4j?
I imagine that you have to implement the logic about relationships and queries yourself and spread the I formation across at least two relational tables. I’d hope for graph databases to do that for you. Is that not the case?
phkx··on Ask HN: What do you use for a personal database?
I like the question for how differently it gets interpreted;)

I personally would like to toy around with some graph database for knowledge management but haven’t found the time to get into it, yet.

Other than that, it’s dendron (and git).

phkx··on Why is every layoff 10-15%?
> One venture firm I know is encouraging companies to assume they should cut 50% and then use financial modeling to prove otherwise.

Is there any common tooling to do that kind of financial modeling other than spreadsheets?

phkx··on Overfitting and the strong version of Goodhart’s law
To me, efficiency means achieving a desired goal while consuming a minimum of resources (time, energy, space, …).

If the goal is defined in a too narrow scope, i.e. your ‚dumb‘ definition of efficiency, the flexibility may be missing. Still, that particular goal may be reached efficiently.

So it’s not an issue with the definition of efficiency, but rather with scoping the problem. As the article states, it may not always be possible to scope the problem in an easily measurable way, hence optimizing for proxy targets.

phkx··on Board Games and Markov Chains
Another nice post in the same direction by Jake VanderPlas:

https://jakevdp.github.io/blog/2017/12/18/simulating-chutes-...

phkx··on WeatherKit
It‘s the first time that I have come across the term ‚hyperlocal‘. As far as I understand in this context it means ‚high spatial and temporal resolution‘. Is that correct?

The Wikipedia article states that hyperlocal is used for information, which is relevant to the population of some given community. Does this always refer to a geographically defined community or has it been extended to other logical communities, as well?

phkx··on Ask HN: How to improve as a struggling junior software engineer?
I agree to the other comment, that there should be some controls or at least a documented release process to prevent changes to prod without a review.

I must say, that I don‘t fully get that example with the prod account. Sounds like it is a larger place where the ‚ticket‘ went to some other team to e.g. change some configuration of the prod stage. If we‘re talking about changes to the code, there should be code reviews from which you get feedback and can learn from it.

Overall, there seems to be a lack of well-defined processes and basic documentation and little awareness for onboarding tasks.

Even if no one had done some of the things you were tasked to do before - could you have asked the other devs how they would approach the task? Are there some dailies in which you can describe what you‘re doing and get feedback from the team?

Going forward, maybe try and identify one of the more experienced devs to build a more trusted relationship and try to get answers to your open ‚basic‘ questions from them. If you‘re afraid of annoying that person, rather batch a few questions and ask them in one session than asking small questions all the time, I‘d say. Depending on how well that goes, you might go further and tell them about your situation as you did here.

Since there doesn‘t seem to be documentation of e.g. the release process, you could write some and get a review for it, saying that you‘d like to prevent similar mistakes in the future.

Finally, if you don‘t find a way within the current team and you start every day in agony, find a new place and prioritize one which feels like it has a more welcoming culture.

phkx··on Atlassian products have been down for 4 days
There’s something hidden in the sprint reports. One of the different views there let‘s you see the stories from any previous sprint. Not sure whether it reflects the state of the stories as of that sprint, though.
phkx··on Spreadsheets Are Hot–and Cranking Out Complex Code
What do are you using spreadsheets for privately? I never dig deep into their capabilities, so I mostly use them to track expenses within some particular scope, e.g. healthcare. When I recently wanted to compare several loans and estimate our financial situation several years in the future, I wrote some Python code and used a Jupyter notebook to enter parameters and make plots. Has any of you done something similar using spreadsheets?

On a side note: I didn’t find a Python library for time series generation (not analysis). Something where you can build some models (e.g. loan, income, expenses) which depend on a common parameter (time) and then evaluate all your models for different values of the common parameter. Right now, I generate pandas series/dataframes and combine them afterwards, which also took some massaging of pandas (which I also usually don‘t use a lot).

phkx··on Paperless-NGX
This is my understanding as an individual in Germany who is not self-employed: Original documents help you to make or defend against legal claims, so for the time being, I'd keep them during any limitation period which applies. Afterwards that paper is not really useful any more (but keeping a digital copy doesn't hurt). I suggest to find out, which periods apply in your jurisdiction.

In my case, I simply settled for the maximum of all the different periods I encountered and file originals by the year after which I can trash them and use the digitized versions for actually working with them (e.g. my tax declaration is now much faster to do). For Germany, I found that 6 years grace period should be fine. 10 years, if you're self-employed.

phkx··on Paperless-NGX
Interesting - will check it out to see whether it is better than my current approach, in which I scan to PDF-A including OCR and let Spotlight do the indexing.

Some additions: I found that black-and-white scans at 300 dpi work for almost all documents, resulting in a small file size and decent readability. Occasionally I switch to gray and 200 dpi and rarely to color. After looking up how long the originals of different types of documents need to be kept for legal reasons, I settled simply for the maximum time (6 years in my case) and file documents in a binder, sorted by the year in which I can discard them. Then, at the beginning of each year, I can get rid off one section of the documents which are older than 6 years. There is a second binder for active contracts (insurance etc). As soon as one of them ends, it goes into the first binder. I‘ve started organizing my Downloads folder in a similar way - sorting stuff by when I think I can delete it (either because it‘s not relevant any more or because I simply never touched it), typically a few months in the future. Both systems have helped to keep the clutter low and.

phkx··on Show HN: Web page that parses and explains the label on a bike tire
There is a barcode scanner on https://schnelltesttest.de/

Their source code is here: https://github.com/zerforschung/schnelltesttest.de

phkx··on No, Covid 19 is not an old person problem
I'm not sure whether the last sentence was already in the article when it was discussed here (and two earlier posts on HN). It reads: "Why is it so difficult to grasp that by killing seniors, you reduce your own life expectancy?"

So for me, the article is not so much about how the numbers in the current pandemic play out. It's about how society treats their 'weak', because each of us could become one of them.

phkx··on SLO alerting for mortals
I like the practicality of analyzing where the customer had pain and adjusting SLOs accordingly. Our system is not open to customers yet, so we‘re lacking historic data with real load (besides system tests, but they currently don‘t include edge cases/chaos). Also, we‘ll probably need to have SLAs from the start, which would be derived from the SLOs, so I need something beforehand.

—-

SLA: service level agreement, values of KPIs promised to customers

SLO: service level objective, internal target values for those KPIs, typically slightly more demanding than the SLA

SLI: service level indicator, measured values of the KPIs to check against SLOs/SLAs

phkx··on SLO alerting for mortals
Is there a common framework how to come up with the values (e.g. 99.9%) set as SLOs in the first place?

I currently want to do that for a service built on several cloud services with their respective SLAs and my approach is to go through the combined probabilities to get an effective error rate. That‘s a bottom-up approach. I‘d combine that we a top-down derivation of what SLOs are required from the business side. If the first number doesn’t fulfill the business requirements with some buffer, we‘ll need to redesign. How do others do it?

phkx··on Reading the web offline and distraction-free
I‘ve been using pandoc to extract texts next to my notes (both in Markdown) in order to add links between them. I haven’t extracted too many pages yet, but the results were reasonable so far, although sometimes lots of html tags remain. Also, none of them contained any math so far.
phkx··on Quantum astronomy could create telescopes hundreds of kilometers wide
I remember how, as a physics student, I was pretty amazed to find that a CD I had lying around created inference rings from the sun shining on it and that I could quite accurately calculate the spacing of the track on the disk. I considered the sun to be a thermal light source - something that should not result in any interference. My conclusion at the time was, that the I was looking at single-photon interference and that the 'lateral coherence length' of the photons coming from the sun must be large. I didn't follow up on this, I'm ashamed to say. But it must me the prerequisite for the attempt to increase the effective aperture of the telescopes.

Another thought that came to me - we already know of a technique to store phase information from coherent sources for practically indefinitely, which is holography. Can anyone tell whether that would be an option for the use case?

edit: I should have spent a little more thought on this comment, but I mostly wanted to get it out of my head and maybe have others pick up on it. The issue with holography is, that the image is created by interference of a reference beam and the reflections from an object. Here, we don't want to image an object, but the light source itself. Maybe we can learn something about the light source when we have multiple holograms created with reference objects...

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