Quick reference: in a new scratch buffer, Quick reference: in a new scratch buffer, In[1]:In[1]: ((with-current-bufferwith-current-buffer (current-buffer) (make-comint-in-buffer (current-buffer) (make-comint-in-buffer "perl""perl" (current-buffer) (current-buffer) "perl""perl" nil nil "-de""-de" "0""0")) )) That’s it! That’s it! Some Some cliclis are not built on readline, and they are a pain to use. There’s no support for editing the input, and every keypress inserts characters –...s are not built on readline, and they are a pain to use. There’s no support for editing the input, and every keypress inserts characters –...
Quick check: do you agree or disagree with the following statement: Quick check: do you agree or disagree with the following statement: If a study finds a result significant at a p=0.05 level, that means they have followed a methodology which produces this conclusion correctly 95 % of the time. If a study finds a result significant at a p=0.05 level, that means they have followed a methodology which produces this conclusion correctly 95 % of the time. Yes or no? Keep that in mind, and we’ll get back to it. Yes or no? Keep that in mind, and we’ll get back to it. I’m reading the Fisher book where he popularised the p-value I’m reading the Fisher book where he popularised the p-value1111 Statistical Methods for Research...Statistical Methods for Research...
This article is seven years old, but it was never published. I don’t know why. This article is seven years old, but it was never published. I don’t know why. mpimpi is not meant to be used. It is a low-level interface designed to build libraries upon, because it is expensive to develop supercomputing libraries tailored to each specific high-performance number-crunching cluster system, so libraries are built on is not meant to be used. It is a low-level interface designed to build libraries upon, because it is expensive to develop supercomputing libraries tailored to each specific high-performance number-crunching cluster system, so libraries are built on mpimpi, which is then implemented on the high-performance clusters. This means , which is then implemented on the high-performance clusters. This means mpimpi is... is...
I forgot to write a retrospective for the 2024 Q2 Quarterly Cup, because my approach to forecasting has become kind of boring: I only do it by gut feeling. No research, no analytics, not looking at the community prediction. This is not because my gut feeling is so great – it is because I have too many other things going on that I cannot take the time to forecast more accurately. I forgot to write a retrospective for the 2024 Q2 Quarterly Cup, because my approach to forecasting has become kind of boring: I only do it by gut feeling. No research, no analytics, not looking at the community prediction. This is not because my gut feeling is so great – it is because I have too many other things going on that I cannot take the time to forecast more accurately. I still want to share what my accuracy is, though, in the interest... I still want to share what my accuracy is, though, in the interest...
I have long struggled with understanding what probability-generating functions
are and how to intuit them. There were two pieces of the puzzle missing for me,
and we’ll go through both in this article.
I have long struggled with understanding what probability-generating functions
are and how to intuit them. There were two pieces of the puzzle missing for me,
and we’ll go through both in this article.
There’s no real reason for anyone other than me to care about this, but if
you’ve ever heard the term
There’s no real reason for anyone other than me to care about this, but if
you’ve ever heard the term pgfpgf or or characteristic functioncharacteristic function and you’re curious
what it’s about, hop on for the ride!
and you’re curious
what it’s about, hop on for the ride!
An acquaintance was feeling what could have been early symptoms of illness, but wanted to run a 10k race later that day. They approached me because they sensed there was a statistical problem in there: how should they react to symptoms getting worse during the race? Is that a sign to quit, or is it likely to be a false positive? An acquaintance was feeling what could have been early symptoms of illness, but wanted to run a 10k race later that day. They approached me because they sensed there was a statistical problem in there: how should they react to symptoms getting worse during the race? Is that a sign to quit, or is it likely to be a false positive? The conclusion was surprising and interesting, so for this article, I’ve recast the problem in terms of site reliability... The conclusion was surprising and interesting, so for this article, I’ve recast the problem in terms of site reliability...
Engineering EnigmasEngineering Enigmas is simplified Tarot reading for working engineers. is simplified Tarot reading for working engineers. Any time you feel stuck and need help in finding a way forward, open that web page and follow the advice given. You may have to be creative in how you interpret the advice in order for it to apply to your situation – that’s intentional. Any time you feel stuck and need help in finding a way forward, open that web page and follow the advice given. You may have to be creative in how you interpret the advice in order for it to apply to your situation – that’s intentional. Don’t refresh the page until you get advice that suits you better. Take what you are given... Don’t refresh the page until you get advice that suits you better. Take what you are given...
My new laptop11 Actually, it’s not new – I bought it refurbished from a dealer with good reputation. I have long rejected buying electronics anything but new, but I am reconsidering. This is a test! is a ThinkPad P52, with one of those dual gpu deals. I’m irrationally scared of running Linux with dual gpus, so I decided to try running Linux inside a Hyper-V vm in Windows. Assuming...
Table of Contents I was nerd-sniped. Out of the blue, a friend asked me, If you would build an in-memory cache, how would you do it? It should have good performance and be able to hold many entries....
The strange character in the middle of the title is a maths symbol pronounced therefore. When looking for a new job I got interviewed by a ceo who had formerly worked as a security advisory consultant. This meant their job used to be advising large organisations on the status of the softer parts of their security systems: people, processes, information barriers, etc. This was something I’d always been curious about, so I...
Using tags is hard. It’s easy to accidentally fall into tagging anti-patterns, such as creating tags that are synonyms to existing tags, or one-off tags for single pieces of content, or tags so vague as to be meaningless in practice. I know because I made those mistakes on this site! Did you know, for example, that there were 14 tags on this site that were only applied to one article? Or that the notes tag was applied haphazardly to articles with...
In the middle of the night, 41 years ago, Stanislav Petrov did absolutely nothing at the most important time to do so. This is an invitation to find an opportunity today to use one of Deming’s favourite exhortations: Don’t just do something; stand there! Sometimes disobeying orders and thinking for oneself is what...
Our first child was born mere weeks before covid-19 came to our part of the world. As a result, they were effectively locked down for the first 1.5 years of their life until they started going to daycare. This had the effect that for those 1.5 years, they were not sick a single time. At some point they turned three, and in total, had been sick 22 times until then11 With an average duration of 4.4 days, meaning us...
Back in 2018 I wanted to turn this into a more ambitious article but that never
happened. I do like the plots, though, so I’m publishing it mainly to show them
off.
At some point in 2012 or 2013, something weird happened. After years of nothing,
object detection accuracy started going up.
Then it brought with it speech recognition.
There’s some 2015 research out of Microsoft titled Code Reviews Do Not Find Bugs11 Code Reviews Do Not Find Bugs; How the Current Code Review Best Practice Slows Us Down; Czerwonka, Greiler, Tilford; IEEE International Conference on Software Engineering; 2015. which seems strangely named because reviewers do find bugs. Here’s what the authors say: Contrary to the often stated...
The Python Developers Survey 2023 has an interesting result that is incorrectly reported. By incorrectly, I mean the raw data is there, but there is no attempt at presenting it in a meaningful way. I’m talking about the professional experience level of Python programmers. The...
For the past few days, I have been toying with an idea for a board game. To test it out, I wanted to write a simple implementation of it. Here’s an example of a type we might need in a critical phase of the game. In[1]: -- | A quote for a proposal. data Quote = Quote { _proposal :: Proposal , _premium :: Int ,...
Just after I published the previous article on bubble sort, I stumbled over another account claiming bubble sort is somehow more robust than better algorithms (emphasis mine):11 I should clarify that I generally agree with the author’s sentiment. It’s just...
One of the coolest techniques I learned from Deming (and I have learned many cool techniques from Deming) comes not from his more popular books, but from Some Theory of Sampling11 Some Theory of Sampling; Deming; John Wiley & Sons; 1950. Deming never gives the technique a name, because to him it’s just an...
Let’s say we want to visualise a few grouped measurements in an article, and we need to use Unicode box drawing characters for it. We might draw it like so, for three groups: ┌──────────┐ │o o o│ └──────────┘ ┌─────┐ │o o│ └─────┘ ┌─┐ │o│ └─┘ After finishing the article, we proof-read it a week later and realise this is the wrong type of visualisation. What we really want is a stacked bar chart. The three...
Barry Jones has written an excellent article on why story points are pointless. I believe his core arguments can be expressed more succinctly. In my reading of it, there are two of them: Effort estimation needs to be grounded in reality to be meaningful. Story points are – by design – separate from reality, and thus not meaningful. Within...
The case was that a sequence was supposed to be sorted, but it wasn’t critical if it wasn’t. I.e. the more well-sorted the sequence was, the better, but everything would work okay-ish even with a random order. The sequence couldn’t be sorted up-front for two reasons: This was a soft-realtime application, so at no point could the sequence be sorted without blowing several deadlines. The sequence itself changed and was replaced every now and then, so in...
I have read the first half of Traffic Flow Fundamentals11 Traffic Flow Fundamentals; May; Pearson; 1990. and since I have never shared how I write my flashcards, I figured I might take the opportunity to do so. This first half of the book generated around 120 flashcards. I wouldn’t normally make so many for just half a book, but this touches on an area which I have wanted to learn more about for a long...
We are now halfway through the period covered by the acx 2024 prediction contest11 Well, we were when I first wrote this – but at the time of publishing slightly more time has passed., and we have had five questions out of 36 resolve. On those, I have been somewhat lucky in my predictions – but that doesn’t say much. What we can do instead is assume the current community prediction is an accurate assessment...
I have been an llm skeptic. I evaluated them early on11 Before ChatGPT, to
give it context!, but at the time my experience was that useful results
required a lot of work. A lot of things coincided, and I decided to give llms
another shot.
I created the following shell script, named it just q, and placed it in my
path.22 This calls out to
I was reading William Sealy Gosset’s paper where he introduced the t distribution for small-sample hypothesis testing.11 The Probable Error of a Mean; Gosset a.k.a. Student; Biometrika; 1908. In it he derives the distribution analytically, but also adds that Before I had succeeded in solving my problem analytically, I had endeavoured to do so empirically. The material used was a correlation...
I have many times had requests for delivering updates to this site via email, and perhaps even sharing some less formal observations through that avenue. This has now become possible because as we are approaching the ten-year anniversary of this web site, Justin Duke over at Buttondown reached out and very generously offered me to use their service for free. I had already been eyeing Buttondown as it...
When I started this website up – dear $deity – ten years ago, I worked my first real job at a place that didn’t do software development very well, and so I planned on writing about things that were
I’m reading The Idea Factory11 The Idea Factory: Bell Labs and the Great Age of American Innovation; Gertner; Penguin Books; 2012., and somehow, through it, stumbled over an article by Shockley about individual productivity in research.22 On the Statistics of Individual Variations of Productivity in Research Laboratories; Shockley; Proceedings of the ire;...
What draws power in a washing machine is probably (a) heating water, and (b) running a motor. So to figure out a better estimation method, we can include configured temperature and centrifuge speed in the table, as well as how long the machine thinks the configuration will run for. The difference between configurations D and E isn’t shown in the table, but in E the “Eco mode” was activated.22 And it did indeed reduce the average power draw...
After I made the first Ship Investor game all that time ago, I continued learning about the Kelly criterion, and made a second game in which you can learn to apply the same principles to a more continuous situation. This is closer to real-world financial investing. Play Ship...
A few years ago I made a simple web game to practise applying the Kelly criterion to binary bets. Play Ship Investor here if you want. You will be presented with a situation where you have to invest in an opportunity that has some probability of suceeeding, and some return-on-investment if it does. Your job is to decide how much you invest in it. Invest too little, and you won’t...
I want to introduce my children (small single digit ages) to tabletop-style role playing games, but they’re a little too young for the full deal. Instead, we have experimented with creating interactive stories where I give the children an objective, I narrate but pause frequently to let them make choices, and then I come up with consequences of those choices. To keep it interesting, I’m trying to use settings they know from books and tv shows....
A few months ago I started trying to write a solver-like program for the card game of Uno. A solver is a program that, given any game state, can tell the user what the optimal next play is. There were three reasons I wanted this for Uno: My son was really into the game at the time11 He still likes it, but he is not as obsessed by it as he was...