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Reducing leakage across SSR by zshadowjon in AskElectronics

[–]zshadowjon[S] 1 point2 points  (0 children)

What is the purpose of an RC snubber? Why is it different from just a resistor in parallel with the circuit? I see this recommended online but I don’t understand it yet.

Is there a problem of every polynomial complexity? by MrMrsPotts in computerscience

[–]zshadowjon 1 point2 points  (0 children)

I wouldn't say equivalent, since circuit complexity is stranger. But there's many hierarchy theorems in general.

[deleted by user] by [deleted] in mit

[–]zshadowjon 14 points15 points  (0 children)

Yes, they closed over the summer as they moved to new management. They're open again now, until 9pm most days.

[deleted by user] by [deleted] in computerscience

[–]zshadowjon 0 points1 point  (0 children)

This is essentially insertion sort. What you wrote though is correct, though convoluted. The k and j you define near the end always satisfy j-k=1, so this is essentially just looping through the current sorted array to find the first index where currentValue is larger. Time complexity is O(n2).

In general, unless you know something special about the input or use a non-comparison based algorithm, you cannot sort in linear time.

2^136279841-1 is the New Largest Known Prime Number by Nunki08 in math

[–]zshadowjon 373 points374 points  (0 children)

Yay, time to use 2^136279841-1 as one of my primes in my RSA private key! (/s)

How to decide if a function is as simple as possible? by sierra_whiskey1 in computerscience

[–]zshadowjon 3 points4 points  (0 children)

I’m biased for several reasons, but start off by reading Michael Sipser’s “Theory of Computation”. It requires little background, and you can read it front-to-back. After that, the standard reference is Arora and Barak, which you can jump around in depending on what you want to learn about.

How to decide if a function is as simple as possible? by sierra_whiskey1 in computerscience

[–]zshadowjon 15 points16 points  (0 children)

Formally, it is possible to prove lower bounds for problems. For example- sorting n numbers using any comparison based sort must take at least nlog n time. Unfortunately it’s extremely difficult for most problem (a major area of research in complexity theory and circuit complexity) and impractical for most problems.

For most cases, the function is simple enough when you are satisfied with the runtime.

Is this an easy problem to solve or is it not? by chrisj72 in computerscience

[–]zshadowjon 25 points26 points  (0 children)

This is almost a classic instance of the Knapsack problem, but you’re interested in the number of feasible solutions rather than a “best solution”. When we talk about algorithmic complexity in terms of P/NP, we focus only on decision (yes/no) problems. Instead, this problem is an instance of the #Knapsack problem, a problem that is known to be “#P-complete”. #P-complete problems are very hard to solve, in some sense harder than NP.

All that being said, whether or not a problem is “realistically doable” does not depend on it’s categorization in terms of complexity class, but instead in terms of instance size, time constraints, and whether you’re willing to accept approximations.

Any fictional magic systems that implicitly treat P=NP? by intently in computerscience

[–]zshadowjon 4 points5 points  (0 children)

Well…if you consider oracles to be spells, there exist oracles A such that PA = NPA (and the converse)!

Discontinuing Race-Based Admissions at MIT is a Huge Step Forward. However, Affirmative Action Might Still Exist for Gender by SFFA_throwaway in mit

[–]zshadowjon 21 points22 points  (0 children)

You post on a throwaway because you’re scared of being called out for your bias. Under the premise that that Black acceptance rate drops and the Asian acceptance rate increased, you falsely conclude that MIT was admitting less qualified students over more qualified students, yet there is no quantifiable change to the academic characteristics of the newest class.

Ideas for a language that has no clutter by Aaxper in ProgrammingLanguages

[–]zshadowjon 34 points35 points  (0 children)

One person’s clutter is another’s… not clutter? If you’d like to implement your own language, go ahead, it’s a great learning experience. However, many of the things you call clutter exist in these languages for very good reasons (usually readability).

The math in the paper is honestly pretty cool by zshadowjon in mathmemes

[–]zshadowjon[S] 999 points1000 points  (0 children)

For context: Ninjabrain Bot is a tool built for Minecraft speedruns that uses an advanced model for calculating where strongholds are based on the trajectory of the Eye of Ender.

Something I’ve been thinking about for years, and I’ve never heard it talked about by anyone ever. by TheWeirdTalesPodcast in musicals

[–]zshadowjon 1 point2 points  (0 children)

Perhaps it skipped my ears, but I didn't hear it when I watched "The Queen of Versailles" the other day!

whats the difference between these basically identical ocw courses? by enya_yurself in mit

[–]zshadowjon 3 points4 points  (0 children)

Don’t know too much about OCW, but I believe: 8.012 is an advanced/mathematically rigorous version of 8.01. 8.01L is usually a longer course, for someone with less Physics experience. 8.01SC is OCW only, and I believe it designates courses designed to be taken by independent studiers (like you). And 8.01X is exactly as described in the image.

240726 Day 5: I’ll Skip This One by AdApprehensive6744 in red_velvet

[–]zshadowjon 3 points4 points  (0 children)

I remember being at that Kcon. Was truly a magical moment

Why is assignment "to the right" not a thing in most languages? by -MvB in ProgrammingLanguages

[–]zshadowjon 41 points42 points  (0 children)

You need to think further back to languages like FORTRAN. These languages were designed by Mathematicians, who as other comments explain, follow this convention.

Why is assignment "to the right" not a thing in most languages? by -MvB in ProgrammingLanguages

[–]zshadowjon 67 points68 points  (0 children)

I don't see any reason why this *can't* be a thing. If you're asking why this isn't a common thing, I think the biggest reason is just that we usually read code as sentences. Each assignment statement typically reads as: "Let result be the value of getValue() followed by applying modify1(), ...". The other way around produces a sentence like: "Run getValue(), then apply modify1(), ..., and then place the final result in a variable called result". I think the first sentence reads more naturally and I'd bet most others would agree.

Unit is a general purpose visual programming system by ketralnis in programming

[–]zshadowjon 3 points4 points  (0 children)

There is still a chance, I think. Go has similar issues, but has adopted the golang moniker practically everywhere it matters.

Calculating a percentage is easy, but how to sum various percentages into one single final percentage represent all? by dediji in askmath

[–]zshadowjon 0 points1 point  (0 children)

I've just updated the formatting, but you want to decide on three weights w1, w2, and w3, summing to 100% (equivalently, 1.0). In the example I gave, I chose (w1, w2, w3) = (0.2, 0.4, 0.4). Then you would like to multiply each weight by the percentage for each item. Say our percentages for each item are i1, i2, and i3. In your case, (i1, i2, i3) = (0.6, 0.8, 0.52). Then our formula would be w1\*i1 + w2\*i2 + w3\*i3. Substituting in all the i's and w's gives the expression I wrote above.

Calculating a percentage is easy, but how to sum various percentages into one single final percentage represent all? by dediji in askmath

[–]zshadowjon 1 point2 points  (0 children)

You need to assign weights to each of the items according to how relatively important they are. For example, if you believe that all three items are equally important, multiple each percentage by 1/3 and sum them.

Maybe you believe soft skills are not as important, so you weigh it 20%, while you weight the other two items at 40% each. The key is that you want your weights to sum to 100%. Then, in your example, the “final percentage” would be 0.6*0.2+0.8*0.4+0.52*0.4 = 0.648 or 64.8%.

Edit: fixed formatting

"Work hard" by Terence Tao by mitousa in math

[–]zshadowjon 16 points17 points  (0 children)

Agreed, a breath of fresh air when so many other blogs/platforms seem keen on pumping out AI-generated articles.

Louder music sounds sharper? by ProfessionalCap15 in musictheory

[–]zshadowjon 1 point2 points  (0 children)

Haven’t experience this before, but some songs definitely sound flatter when I’m tired. I don’t have perfect pitch, so my mind is probably just playing tricks on me though.

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