HNHacker News
TopNewBestAskShowJobs

donquichotte

2,775 karma · joined July 31, 2013

submissionscomments
donquichotte··on How NASA Designed a Helicopter That Could Fly Autonomously on Mars
Do you know why radiation hardening is not needed for the Ingenuity? Is there a mechanical shield? Or is it just the shorter runtime that makes the use of an off-the-shelf processor acceptable?
donquichotte··on Ask HN: What are the best websites that the Anglosphere doesn't know about?
mikrocontroller.net, a German resource and forum for electronics, microcontrollers and low level programming.
donquichotte··on Chick Corea has died
It's certainly not a common word in German. In fact, this is the first time I've ever seen it, and all google search results are either dictionary entries or English articles that can be attributed to the Anglosphere's obsession with German compound words.

Source: native speaker, reasonably literate

donquichotte··on Haxe 4.2
I just had a look at the free chapter of your book, the page layout looks very appealing and clean. Would you mind sharing the stack you used to typeset those pages? Is pandoc involved?
donquichotte··on The Art of the Cover Letter
> “No one will read this,” my advisees lament, often as I am reading their cover letter right in front of them. I know they mean that no one important will read it.

I think what they mean is "no one who is in a position to give me the job I want is going to read this", they clearly went to the author because they think his help will increase their chances of getting that job.

When writing a cover letter, which is quite common when doing direct applications in Switzerland, I never know who I'm addressing, and knowing your audience is a key factor when designing poignant communication.

Will it be a HR person? A tech lead? A team lead? Will they appreciate the ugly-but-hard-to configure LaTeX template I used, the hand-coded postscript to generate the symbols for the telephone and the letterbox? Will they know that if I write "C" in the list of programming languages, that does not mean I am proficient in C++? That a seemingly tangentially related job I am mentioning is actually solving the same problem, but in a different industry?

The result of this is that most cover letters I have written contain generic platitudes, to the point where I now have a makefile and just make minor adjustments like company names and addresses, plus some tweaking, before sending it out, with a reasonable success rate.

Now that I'm thinking about it, maybe it is true that nobody is reading these.

donquichotte··on The Feminine Physique: On Women's Bodybuilding
> Positive attention from strangers is a singularly terrible thing to hinge your wellbeing on, but man. It sure feels nice.

The addictivity of facebook/youtube/instagram/hackernews upvotes condensed in a single sentence, great insight!

donquichotte··on Ask HN: What is your “I don't care if this succeeds” project?
Some of these are actually rather quotable.
donquichotte··on Claude Shannon Demonstrates Machine Learning (1952)
What a grave misunderstanding! What he is demonstrating is remembering, or memory.

It appears that the state of the mouse is [X, Y, Heading], where X and Y are discrete positions in the available cells.

Once the maze has been solved by "a rather involved strategy of trial and error", the solution is saved, and for any of the known states, the mouse "remembers" its way to the exit of the maze.

donquichotte··on Gary Numan: 'One of my songs got over a million streams – I got £37'
That does not align with my experience. On Christmas 2019, I recorded an album [1] of 9 "Snake Jazz" songs, each 30 seconds long, as a joke on a Rick and Morty episode. Published the album on CD Baby, and had them distribute it on all available platforms. Publishing cost me 80$.

Now, about a year later, I have earned 0.47$. 0.33$ of it come from Spotify, where I raked up a full 131 listens, averaging at 0.25 cents per listen. 0.25cents * 1e6 would amount to 2500$, which is admittedly still not much, but two orders of magnitude off from what is reported here.

That being said, I believe the main source of revenue for bands has been concerts in recent years (not 2020 though), with ever-increasing prices charged for live performances. I gladly accept that though - it is quite appealing to cut out the middle-man that were Music Studios up until the early 2000s.

With the barrier of entry to record an album ever-decreasing (using a Roland Octacapture, Reaper DAW, a Shure SM57 and lots of sweat you can get far), pretty much anyone can record an album in decent-ish quality in the comfort of their home, there is no more appeal to pay expensive studios to do a recording for you.

[1] https://music.youtube.com/browse/MPREb_2nw3eEydV25

donquichotte··on Show HN: History suggest box for your shell
Same here. With fzf, you don't search - you find. One of my most powerful bash aliases is

alias fzubl='fzf -m | xargs subl'

donquichotte··on The Internet Is for Porn
> virtually anything sex related, apart from toys, cannot be purchased with credit or debit cards

So after all those years, we have finally found a use case for cryptocurrencies!

donquichotte··on What is your favorite C programming trick? (2009)
1. Finding the size of a struct member (lifted from the Linux kernel)

#define FIELD_SIZEOF(t, f) (sizeof(((t*)0)->f))

2. Not strictly C: using `pahole` to analyze how structs are laid out in memory

https://linux.die.net/man/1/pahole

donquichotte··on Total cost of ownership: Mac versus PC in the enterprise
What a strange article!

"Every computer on an enterprise network needs a set of basic services. In particular, power and internet must be available."

Power? In the sense of [Nm/s]?

And the graphics! Why is the Mac-Square larger than the PC square in the second graph? Why does the "Hardware and essential software" square not contain references to hardware or software, but concepts like "encryption" or "deployment"?

I have a really hard time understanding the point of that article.

donquichotte··on Ask HN: What is the best money you have spent on professional development?
1) Tuition for university (600$/semester * 10 semesters)

2) Sublime Text (80$)

donquichotte··on Best aspects of C
Exhibit B: yes, the command that repeatedly prints `y` to stdout. Exhibit C: all handling of time, with time_t, struct timespec, timeval etc. We should just have a 64 bit uint representing nanoseconds from epoch, which would give us 585 years and get rid of much nonsense.

[1] https://github.com/coreutils/coreutils/blob/master/src/yes.c

donquichotte··on Pygame 2.0
I am working at a company that is tracking vehicles using GNSS antennas. When designing the vehicle dynamics model for the Kalman Filters, I found it useful to have a graphical representation (including error ellipses, velocity vectors etc). Turns out that pygame was a great fit for that type of visualization.

Fast forward to two days ago, when I was idly watching George Hotz design a monocular visual SLAM prototype in 11h. Much to my surprise, one of the first things he fires up is pygame for visualization [1]!

[1] https://youtu.be/7Hlb8YX2-W8?t=701

donquichotte··on I Hate Coordinate Systems
I'm working on a system that transform data from Long/Lat/Alt (WGS84) to a local tangent plane (LTP) East/North/Up coordinate system. To go from WGS84 to LTP, the coordinates first need to be transformed to Earth-Centered Earth-Fixed (ECEF) coordinates and then translated and rotated.

I was quite surprised to find that while it is straightforward to go from WGS84 to ECEF with a closed form, the other way, from ECEF to WGS84, needs to be computed iteratively [1] and is not trivial to find.

[1] https://en.wikipedia.org/wiki/Geographic_coordinate_conversi...

donquichotte··on I Violated a Code of Conduct
> Why don't contributors openly reject this stupid system (not the rules themselves, which sound fine) and unseat these self-proclaimed procurators is beyond me.

Indeed. It seems like the winning move is not to play, but I guess that applies to all cyber-bullying. Avoid the offending environment (in that case, JupyterCon) and contribute to a place where discourse is appreciated.

donquichotte··on The self-driving car is a red herring
Indeed! Merge onto the highway, relinquish control, program the exit you want to take and lean back.
donquichotte··on Be prolific
To improve, busy work is not enough - some kind of quality control is needed to provide feedback, like mentioned in the "Share your Work" paragraph.

I have been playing guitar for 28 years and barely improved in the past 15 years - after a teenage burst of disciplined, daily drills with metronome and recording a lot of music, I still regularly doodle and learn new songs, but it is just not enough to give me escape velocity from the current plateau.

donquichotte··on Ask HN: What are some problems solved in unrelated domains?
A bit late to the party, but: Statistics and Robotics, Statistics and Digital Communications.

Many filters in Robotics (Kalman Filter, Particle Filter) and many concepts in digital communication (Modulation Schemes, Filters, ...) are firmly rooted in statistics and require a decent applied understanding of the area.

donquichotte··on Petit Fat File System Module
Indeed, his work on SD cards is also excellent, very applicable and has been invaluable for me when working with SD cards on STM32 microcontrollers.
donquichotte··on How to Drive on Sand Without Getting Stuck (2017)
Some nice insights! I learned motorcycling on sand (and through rivers!) while crossing Mongolia, west-to-east. Key takeaways:

- recon on foot if uncertain (this is also in the article)

- always keep a positive torque on the rear wheel and let the front wheel find its way

- don't get scared, the front wheel is supposed to skid a little and the rear wheel is supposed to slip a little

donquichotte··on Math.min(Math.max(num, min), max)
Can you give an example where median([a, min, max]) is not equal to clamp(a, min, max), given max >= min?
donquichotte··on Math.min(Math.max(num, min), max)
Luckily, this is a solved problem for go.

  func helper(a float64, c chan float64){
      time.Sleep(time.Duration(a) * time.Second)
      c <- a
  }
  
  func clamp(a float64, min float64, max float64) float64 {
      c := make(chan  float64, 3)
      go helper(a, c)
      go helper(min, c)
      go helper(max, c)
      _, out, _ := <-c, <-c, <-c
      return out
  }
donquichotte··on Autodesk criticised by architects
It's also remarkable that while in many areas with "theory-heavy" software development (e.g. compilers), the open-source solutions are arguably better than the proprietary ones, this is not at all the case for mechanical CAD software. I wonder whether the overlap of people who can program, people who know enough math to develop a mechanical CAD software and the people who care about mechanical CAD is just too small for a successful open source effort.

Yes, there is FreeCAD and OpenSCAD, but every time I try to use them, I give up in the end and whip up something in Fusion360.

donquichotte··on TensorFlow, Keras and deep learning, without a PhD
Tangentially related (and also using the ubiquitous MNIST dataset), Sebastian Lague started a brilliant, but unfortunately unfinished video series on building neural networks from scratch.

This video was an absolute eye-opener me [1] on what classification is, how it works and why a non-linear activation function is required. I probably learned more in the 5 minutes watching this than doing multiple Coursera courses on the subject.

[1] https://www.youtube.com/watch?v=bVQUSndDllU

donquichotte··on Pixelopolis, a self-driving car demo from Google I/O built with TensorFlow-Lite
It's in TFA: "the Pixel 4 also controls the motors and other electronic components via USB-C".

There's an STM32 micro-controller which presumably acts as an USB slave and controls the servos.

donquichotte··on Mcfly – neural-network powered directory and context-aware shell history search
Of course it is. fzf [1] is all you need, and it behaves deterministically.

[1] https://github.com/junegunn/fzf

donquichotte··on Lua 5.4.0
Love2D is indeed excellent, and integrates well with the Tiled map editor. It makes making games almost as easy as Macromedia Flash did!
← PreviousPage 4 of 18Next →