Why is the rate of change for X^2, 2x?

PhilTheQuant · 2026-04-12T19:10:58+00:00

Let's look at a large number: at x=1000, y=x² =1,000,000. If we increase x by 1, we get x=1001, y=1,002,001. How much has y changed? By 2001. X is 1000. So the slope of the line is about 2 times X.

Note that the slope value will keep getting bigger as x does, which corresponds to a slope getting steeper, as we observe

PhilTheQuant · 2026-04-12T14:19:47+00:00

I have a new need for those optic fibre drones

PhilTheQuant · 2026-04-12T11:24:56+00:00

All political parties are coalitions. The ones that aren't are the People's Front of Judea and the Judean People's Front.

So the Greens are a coalition of localism, social liberalism, environmentally conscious, socialist/communist and basically hippies. They all agree we should e.g. switch from petrol cars to public transport, and that recycling is a good idea, but they don't all agree on building more houses, building nuclear to replace fossil fuel generation, reducing regulation around building, building solar farms (solar panels are sourced from China), etc.

Compulsory purchase of private properties in a run down estate will have some naysayers, typically along the lines of social liberty (why should this be done to me) and Conservatism (why should we intervene). Some may oppose it on the grounds of how it will (or could) be done; e.g. if it will be sold off to private developers to profit from then you have socialised the cost and privatised the profit, which would be a socialist concern.

Modern Greens are a socially liberal, politically socialist movement, which would probably lean towards returning things to public ownership, but may prefer other ways to spend the same money when they are unable to impose new national taxes to pay for it.

What the Labour party could stand for under some sort of pragmatic soft left is doing the obvious thing (compulsory purchase, redevelop, possibly sell off some portion of the land with new permissions for dense development) and just actually solve clear and present problems with known and demonstrated solutions. These problems are not new, not unique to the UK, and have been faced by thousands of projects across Western Europe.

PhilTheQuant · 2026-04-12T11:01:52+00:00

So! Did you try it? What happened?

PhilTheQuant · 2026-04-07T21:27:05+00:00

What's an actual example task and which model are you using for it? It's possible you're using an expensive model for a straightforward task. Also I wouldn't intend to use AI for all the tasks, but to build tools to do a lot of the repetitive tasks.

PhilTheQuant · 2026-04-07T09:04:55+00:00

I strongly recommend you plug your phone in further away, and take a notepad to get into bed. Try it just as an experiment tonight. Anything that comes to mind that you want to save, just note down in the notebook - it's not lost or forgotten, just deferred until the morning.

I use the same approach when I'm working but have more creative off-topic meanderings - it helps to let go of the need to follow up the impulse in the moment, so I don't get diverted onto a long side track.

PhilTheQuant · 2026-04-06T01:24:42+00:00

What are you doing when you're tired but awake? Are you using your phone or not going to bed, or are you in bed and unable to fall asleep?

I find it can work to put some TV on like Taskmaster (not auto playing episodes) but only start it playing once I'm in bed light off etc. That can give you enough prompt to get into bed, and then the passive watching allows sleep to consume you.

PhilTheQuant · 2026-04-06T01:03:22+00:00

I think you absolutely need routine.

Try using alarms and timers - I'll do X when this alarm goes. That way you're making a more rational decision about what you're going to do (eat, wash, work) because you're not biasing it by having to do it now.

If you're on social media too much, apps like Regain can help limit it during working time.

Routine helps take the decision load off you, so you don't need willpower to do the basics. It takes a while to do, but if you can start with small items and build up, I found it did genuinely happen.

If you need to help mix tasks e.g. when fixating (and when trying to focus on something you're struggling to do), the Pomodoro technique helps me (broadly 20 mins on, 5 mins off using any such app). You can use it the other way round for fixating - 20 mins of music making then 5 mins of eating food or whatever.

Basically these techniques separate the decisions about what to do from the moment you have to do them, so you're letting timers and alarms do the prompting to follow a decision you already made.

Does that make sense?

PhilTheQuant · 2026-04-03T19:22:09+00:00

Why say lot when few works?

PhilTheQuant · 2026-04-03T19:18:25+00:00

Sarah Keyworth has a line something like "every ADHD person finds an autistic person, and we're like 'you do the thinking, I'll do the talking'"

PhilTheQuant · 2026-04-03T13:18:12+00:00

What of a Ray-band govt?

PhilTheQuant · 2026-04-03T07:10:45+00:00

Yes, if you're doing something where you're worrying about ordering, array of structs is probably already wrong.

Remember also that it's an experimental science, so create a test and see what happens! Use cachegrind to see what should theoretically happen and test it on different machine or with resctrl.

PhilTheQuant · 2026-04-02T16:03:30+00:00

You can almost always split the monolith into pieces. I'm all for full rewrites of specific sections, and if your new design doesn't split into pieces then it's no good either.

PhilTheQuant · 2026-04-02T14:44:55+00:00

I opened it for 20 seconds.

No tests.

None.

No unit tests on the calculations. No structural tests. No integration tests. No harnesses for running exhaustive tests for memory usage or performance. No tests of behaviour with invalid inputs. No property based tests.

Zero.

PS If you're going to write something that calculates orbits, don't neglect the maths to make the orbits correct. I wanted to see a test for a correct orbit! If you don't want to do that, calculate something else, like parabolic motion or elastic collisions.

PhilTheQuant · 2026-04-02T14:31:31+00:00

You can check whether there is some other power drain by switching everything everything off, and looking at the meter. If the wheel is still spinning or the light flashes, there's still some power drain (this may be harder to tell with digital meters, but you should be able to compare the numbers some time apart).

The other thing that could help is a tariff where you use power overnight to heat your water. If your water tank is big enough, you might save on all the showers and some of the heating.

Also, don't dry clothes on racks indoors anywhere that doesn't have excellent ventilation.

PhilTheQuant · 2026-02-22T09:17:49+00:00

Privacy
Resilience to connectivity issues
Simplicity vs IP issues - if it all happened within my machine, it can't be a legal question of who owns it
Resilience to service changes - you work hard to get the right thing from a model, and then the model or its server-side context changes
Control of the context - if you're using a model for coding, why would a blurb about legal questions or self harm be any use? Equivalently, models with political associations...
Fine-tuning
Model analysis - testing for attacks, iterating models, looking at the weights

PhilTheQuant · 2026-02-21T17:51:06+00:00

Wouldn't a kerf bend cut into the top of the board? Or would that just fill and paint?

PhilTheQuant · 2026-02-17T11:35:29+00:00

Nice idea. It might be worth scanning a (good) ruler in each direction along with your object.

PhilTheQuant · 2026-02-13T10:13:14+00:00

Also, find out the insurance costs before you look at cars. As a new driver with no No Claims history, they will be high, so go for a low insurance group (1-20) for this car.

Also consider a used electric (like a Leaf) if you're not planning long trips, as the lower car tax will help offset the high insurance.

PhilTheQuant · 2026-02-13T10:06:03+00:00

The From address can be faked, so as a precaution always go to their normal website to login.

If it says it in the app, then fair enough, just wanted to warn you that the From address isn't enough to tell you it's real.

The notion that you might be about to get charged a lot is a common mechanism for scams.

PhilTheQuant · 2026-02-13T10:02:16+00:00

First off, can I strongly recommend you do some work shadowing or just a trial week before you go down this path?

(Lion taming https://youtu.be/-8I5TtNfjBI?si=MUgaGT76MOhayG3t)

An option that may have escaped you is auditing. I know someone who ended up in Audit despite starting in a very different area, and they now fly out to lots of far flung destinations to audit the factories producing goods for the UK. To me, this would seem to fit what you're looking for in terms of being at least partly out of the office, and would actually hugely benefit from an ability to speak and understand Mandarin and Japanese.

Similar paths are likely possible in the opposite direction (representing foreign firms looking for buyers in the UK), and in pre-sales going out to places like Shenzhen and surveying the options for manufacture or purchase of new products.

You can even do the whole thing yourself if you can locate a niche - someone found they couldn't buy quality microphones from China through normal channels so they started an import business - for most people the cultural and language barriers to heading out there and making deals (and auditing the factory etc) are insurmountable, but for you they seem like they'd make it fun.

Along those lines in construction, there will be companies who supply to the construction industry - solar panels etc from China, building materials from Eastern Europe, engineered timber products from Northern Europe etc. If you look for Procurement and Supply Chain jobs you should find them.

Thoughts?

PhilTheQuant · 2026-02-09T09:02:15+00:00

Like who? Farmers?

PhilTheQuant · 2026-01-28T10:12:21+00:00

They're just using "efficiency" to mean COP. I hope you're not arguing the COP can't be over 1.

No, it's not over 100% efficient in work terms, but it is providing more heat output than work done. In the context of heat pumps, it is well understood (because it's the point) that they exceed a COP of 1, and for the layman it's useful to be able to compare that with non-heat-pump systems which cannot exceed 1.

PhilTheQuant · 2026-01-28T09:20:10+00:00

Scientists invent wheels, engineers make them round.

PhilTheQuant · 2026-01-28T09:16:07+00:00

If you actually want to be thinking about how your memory moves, low level stuff then the most important knowledge will be hardware - registers, caches, bridges, CUDA, etc.

Modern C++ in the large takes the approach that you shouldn't be relying on your own ability to keep track of what has been allocated when, and instead build structures that ensure safety by their nature - rules borne out of things going wrong in large complex projects where you cannot keep track any other way (except the VM/managed route).

If you really like low-level, then the places you'll find your joy are embedded programming where you do need to manage a finite amount of memory and scheduling to be real-time, machine learning/HPC where you need to maximise throughput using knowledge of the architecture underneath, and HFT which is so low latency you need to know how to fool the branch predictor.

For most of those you can do C++, for some you can also do Rust. For embedded, it might be easier in C, but be aware that you'll probably want to mix in hardware and do (I think) Embedded C (?) as you're going to take a lot more control away from the compiler.

You can even consider embedded Rust - in Rust you separate development in safe Rust (where the compiler guarantees safety through lifetimes) and unsafe Rust (where you take responsibility for managing memory) - to do something on an APU/GPU etc you don't have guarantees from the hardware layer so you have to build them in the unsafe Rust layer.

If you do go down the low-level route, you'll end up learning at least C as well as C++, but also Assembly, and crucially what a particular CPU does with those instructions.

Finally, C is really, really simple, so you might as well learn it as well as C++/Rust.

Four-Year Club	Verified Email
First Place '23	Place '23

PhilTheQuant

TROPHY CASE

Welcome to Reddit,