Pffft.... that's what ham radio is for.
(Note: humorous, not ill intent here. An old office mate of mine once kidded me that he thought ham radio was a conspiracy on the part of the world's geography teachers to get people to take an interest in their subject.)
Readit NewsThe article is talking not about the route planner, which I agree usually gives very accurate estimates for specific routes, but the advertised theoretical driving "EPA ranges", which are quite inflated.
However, from what I can tell, the EPA numbers from all manufacturers are quite unrealistic, because the methodology doesn't match real-world driving.
Yes, this is certainly true for ICE vehicles. The measurement methodology is spelled out in exacting detail, and yields highly repeatable results. Realistic? Nope, not at all. Nobody could claim that. But, it is repeatable and comparable, so that you can compare car A to car B. It gives you a strict rank order for vehicles that are driven exactly the same way, it just so happens that no person drives exactly that particular way. The utility is in providing a repeatable point of comparison. Is that useful?... forgive me for saying it, but YMMV.
dbcurtis commented on Math Academy pulled me out of the Valley of Despair mikelikejordan.bearblog.d... · Posted by u/gmays
Can you give more detail on what you mean by it can be a valuable experience with the right people around to help.
My son (7 years old) is gifted in Math and as a parent I find it extremely hard to decide how much I should push him (register him to math competition, weekend math club ...) and how much I should just let him get 100% on exam and not accelerate the learning.
In my experience as a parent, you can provide the resource but don’t need to push. Love of math will happen if it has the right environment. For a 7yo I might suggest looking onto Epsilon camp, and Art of Problem Solving (which is on line).
My own kid went to MathPath (middle school camp by same people as Epsilon Camp). Loved it. “Yes, dad really, I want to spent a whole month of my summer doing math.” The social experience is great for kids to be with other kids that like math.
dbcurtis commented on Python as a second language empathy (2018) ballingt.com/python-secon... · Posted by u/luu
Oddly, trying to occasionally place on the Advent of Code global leaderboard was the thing that got me most fluent in Python as its own language.
Before that, I tended to write Python in a much more imperative style, since C++ is my main language; think for loops and appending to lists. Thanks to AoC, I'm now addicted to comprehensions for transforming and filtering, know the standard library cold, and write much more concise, Pythonic code.
Ha ha, yeah, for sure. It is easy to tell the Python code coming from an experienced C programmer. The thing about Python is, you can just give C a semi-colon-ectomy and it pretty much works. But it isn't Python... it took me a while to get completely pickled in the Python way of doing things. Ramalho's book did more than anything to put my brain into Python mode.
dbcurtis commented on Robotics and ROS 2 Essentials henkirobotics.com/robotic... · Posted by u/dtquad
While it's used in industry sometimes, ROS is really one of those by-and-for-academia tools. There's a reason it's near-universally reviled, and why "migrate off of ROS" is a standing goal at a lot of robotics companies.
There's also a reason why it's a standing goal, rather than a completed goal.
It does little or nothing really well, but it does everything kind of okay.
There's a lot of "alternatives", most of which do something much better, sometimes much much much better, than ROS, but none of which can replace it all completely. PyRobot, Viam, OROCOS, Webots, all of these do some things much better than ROS, but none of them can drop in and easily replace everything without a lot of developer time, often adding new features to the platform.
Sure. A ROS system, being a collection of independent nodes coupled with a publish/subscribe messaging system, allows you to mix and match nodes for whatever. So as a researcher, it is great. It gives you a "good enough" robot for the 98% that is necessary infrastructure for the 2% where you want to experiment/innovate. In an commercial setting, yeah, you run into scaling issues all over the place. Also, the code quality of different stock nodes is highly variable.
So ROS can get you past your A-round -- but count on addressing scalability and stability issues as go. Which is why "write out ROS" is on everybody's to-do list.
In any case, learning ROS is well worth it. As a hiring manager, I know I can easily teach you our system if you know ROS already.
dbcurtis commented on Branchless UTF-8 Encoding cceckman.com/writing/bran... · Posted by u/vortex_ape
Last time I tested branchless UTF-8 algorithms, I came to the conclusion that they only perform [slightly] better for text consisting of foreign multibyte characters. Unless you expect lots of such inputs on the hot path, just go with traditional algorithms instead. Even in the worst case the difference isn't that big.
Sometimes people fail to appreciate how insanely fast a predictable branch really is.
Pretty much. A strongly predicted branch is as fast as straight-line code, for most practical purposes (in modern processors). It is the mis-predicted branch that causes a pipeline flush and a re-fetch and so forth. The whole point of instructions like CMOV is to replace "flakey" branches with a CMOV so that you can execute both code paths and the test condition path all in parallel and grab the right answer at the end. This avoids paying the mis-predict penalty, and gives more time to compute the test condition, which for a branch is almost always only available awkwardly late in the pipeline. So as long as the compiler can do a decent job of identifying "flakey" branches up front for replacement with CMOV, it is a win. And many branches are easy for the compiler to classify. For instance -- if(SomeRareExceptionCondition) handle_exception(); -- for bonus points, move the exception handling code way the heck out to a different text page so that it isn't hanging around taking up I-cache space for no good reason.
My own conclusion about burnout is that it fundamentally comes down to who controls the agenda, and how much you invest in that agenda. I've been burned out. Many years ago, early in my career. My cure: I was in the lucky position that it was a good time to spend a year and half going back to school to knock off a graduate degree that simultaneously moved my career forward, gave me a total change of scenery, and gave me some break time between leaving the job and starting classes, time that I devoted 100% to hobbies and home improvement projects. And of course, an easy-to-tell story when reentering the job market.
So on the topic of agenda... if what you are working on is your own agenda, you don't burn out. You might change the agenda by redefining goals, but in the end, you are sailing your own ship. Not only do you not burn out, it is curative. It is when you absorb someone else's agenda and make it your own to an unhealthy extent that you burn out. Always be computing that dot product between your employer's agenda vector and your own agenda vector. Don't over-invest beyond that dot-product.
dbcurtis commented on Music and Geometry: Intervals and Scales roelsworld.eu/blog-music/... · Posted by u/coloneltcb
That is cool and different. Glancing at the bottom several rows I tend to agree with the classification, as a trained musician. I wonder though, what is (the mathematical principle) behind it that is causing the brightness/ darkness in the sound of these chords?
Don't say "dissonance" (or explain what dissonance is)- that much is obvious, looking for something a bit more detailed, e.g. why 1-2-5 sounds brighter than 1-4-5
It is going to be the relative amplitudes of the overtones. Pure tone (like flute) is bright, many overtones present with the appropriate mix can sound dark (french horn). Next, you are going to ask me for the coefficients, but I don’t know that. Break into the nearest church with a proper pipe organ and start pulling and pushing stops to see what happens. (Or ask your friend the organist to take you so that you don’t get arrested)
dbcurtis commented on Tsunami Warning for Northern California tsunami.gov/?p=PAAQ/2024/... · Posted by u/adastra22
Google some tsumani simulations of the west coast. Prepare to be surprised.
Gmail is not "crippled". A tiny but vocal community of old nerds have a petrified mental model of email that they associate with unix IMAP software from the 1990's, but those concepts do not appear in the IMAP standards anywhere.
For context: I spent 11 years at Intel managing pre-silicon and post-silicon processor validation. No processor that does only and exactly what the Programmers Reference Manual says, and takes the phrase "undefined behavior" seriously, will be successful. Google would do well to adjust their philosophy.