I would guess that it is much more dangerous to modify a modern car because they utilize nontrivial shell geometry to improve the rigidity or to reduce weight. When I was attending driving lessons, my teacher claimed that the specific shape of the windscreen or rear window was a very important safety feature in the scenario that the car rolls over.
The big one is the A pillar on the front. This tends to corrode over time and is often why cars are written off. If it is corroded then the structural integrity of the car is compromised. There is really no repair for it - but a bit of welding can disguise things and get a write off sold as a potential project. The new owner can find out when they take the wings off... or they can find out when the front of the car comes off in the event of a shunt, but in that scenario they only find out very briefly.
That write-off is an economic affair, not a technical one. A-pillars too can be re-manufactured, but it is usually better not to because if the A-pillar is compromised you are looking at a body that will have a whole lot of other damage as well. The bad part about damage there is that you need to build it up from the inside out which means 'undressing' the whole box layer by layer so you can rebuild it properly, and most people will not have the time, the skills (or the jigs) to do this properly. But it definitely can be done, but likely not in a way that is economical.
I can't imagine an A-pillar that is damaged with the rest of the car being deformed as well, the A-pillar of a modern car is ridiculously strong and meant to be the outer boundary of the safety cage for the passengers. Any deformation there and you'll have a deformed bottom, roof, firewall and probably other parts as well.
I think variational problems are more naturally understood through energy minimization. You start with the energy of the system and try to minimize it via derivatives. Then you arrive at a variational problem. The differential equation is then more of an afterthought.
As a teacher, I'd like to use this in presentation slides, i.e. pause the output at specific times and continue only after a button is pressed. Does anyone know if there exists a tool, e.g., to automatically pause MP4 playback at specific times?
I built exactly this in my Manim-based library, code-video-generator [1] (via the code-video-generator command and the --slides flag). It basically turns any Manim scene.wait() call into a pause that I can then advance with a clicker. I used it for this video [2], where I was recording in front of a green screen, but wanted the exact control when the animation continued. code-video-generator played the video fullscreen, which I then captured via obs [3] and used the obs display as a monitor to see if I was pointing at the right spot. Was a bit tricky to get all set up but worked pretty well.
This allows you to e.g. get the current time (get_time) and pause playback (pause). So you just have to write a small script that issues the commands the way you want and you'll be good.
if you are comfortable with LaTeX, you can use the animate package on beamer slides. It does just that, and allows both playing the animation or running it frame by frame (fwd and back).
manim works by generating a "partial movie file" for each animation, i.e. a single mp4 file for each scene.wait() call and so on. The final output just stitches these together.
I did exactly what you want using a small reveal.js plugin that parses the list of partial files generated by manim and inserts the corresponding video files into the presentation in thst order, it worked quite well. Let me know if you're interested and I'll throw it up on a GitHub gist.
I checked some of the references at CDC web page and seems that I won't die any time soon drinking one beer a day (male, non-smoker). E.g., https://pubmed.ncbi.nlm.nih.gov/26286216/
Derivatives then are a higher order function that follow it's definition in all cases. You can't exactly apply it's definition as a limit in cases where it's applied to non-fictions.
I've analyzed performance data from air lubrication vessels with some retrofits included. Frankly, never witnessed over 5% gain. At specific velocity range the gain could be 5% on average if the installation has been really successful. They might be better nowadays.
I'd imagine fuel costs are a big part of the cost of running a ship. Wouldn't a 5% gain be something ship owners would jump at? I realize it would be lower once you account for the added cost of the system and you may not always get 5% but even a savings of 1-2% of a big number is still a big number.
> I'd imagine fuel costs are a big part of the cost of running a ship.
"A 12% reduction in at-sea average speed, known as “slow steaming,” led to an average reduction of 27% in daily fuel consumption and thus fewer greenhouse-gas emissions."
Slowing down sounds a lot easier and cheaper than retrofitting bulbous bows or fancy new air lubrication systems.
That does sound better but I think it would be harder to implement. Convincing people to accept later delivery times is tough. People don't want delayed gratification. US interstate speed limits used to be set to improve fuel economy due to the gas crisis in the 70s. Try to convince drivers that we should go back to a 55 mph speed limit.
I agree with the conclusion, but daily fuel consumption isn’t the right thing to track.
I think this comes out to a 17% reduction in fuel use per unit distance, which still seems quite significant, but maybe changes the trade off point a bit.
no, the comment is the included REPL has it,
and that most editor plug-ins (of which they exist for vim, emacs, sublime, Atom, VS-Code) intended for julia, add the same unicode shortcuts, as well as the usual syntax highlighting, keyword completion etc.
If you don't want to use the, but do want to enter unicode, then you can do it the normal way.
But I feel like the fact that you want to enter unicode but don't want to install a plugin to make it easier is pretty weird.
I guess it could come up if editting someone elses code.
As a general rule most libraries (including the standard libary) make very limitted use of unicode in their APIs, so you don't have to use unicode to work with the library.
I would go so far as to say if a library requires you to use unicode you should open an issue, and get them to add a ascii alias for that function. (julia standard library had just such an issue opened a few versions ago about the compose operator ∘ and not we have a `compose` function to match).
I would also say internally most packages make very limitted use of unicode also.
Even with the plugins it is still a bit annoying to type.
Plus often it would be a less meaningful variable name.
E.g. why say: θ, when you could be saying `departing_assent_angle` or something else that conveys context specific meaning.
Its nice to have the option for when it is clear, but I think pleasingly people only use it in moderation.
