America

That’s fucking cool!

Okay here are the 🫘:

Wavelets:

So the best way to begin explaining wavelets is through analogy to music. (I’m cheating a bit since this explanation is alluded to in the article 😆)

It is a nontrivial practical fact that you can express any reasonable sound as a sum of sine waves. Yes, by combining enough sine waves (which individually “move” for all time) in just the right weights, you can come up with “any” sound you want (edit: including sounds that “start” and “end”. Isn’t that wild?). And then, it turns out that if you give me just the weights, I can give you back the sound itself. And as a final physical fact, it turns out that we hear the weights of any given sound, averaged over some finite window of time (more on this window in a minute). Hence why we can pick out instruments from a band. And lastly, some phenomenon are easier to analyze by looking at the weights; music is an excellent example. In fact, when I mix music in my rapidly diminishing free time, I am often staring at a graph of the weights and seeing this these weights add together and make the instruments work together.

Formally, we use one of the Fourier transform frameworks. Each weight is associated to one unique sine with a given frequency. The size of the weight is called the frequency response at that frequency.

Now for many, many purposes, breaking up a signal in terms of sines is a perfectly appropriate choice. However, what you lose when you choose to look at just the weights is all timing information. (This is why I included the detail about the window in how you hear stuff. If you heard all frequencies over all time with no window, you would not be able to perceive rhythm.) The solution in music often is to simply impose a window on the signal and slide it as the play head moves.

However, we must now leave the realm of music to talk about wavelets in a domain where they are typically used. Now imagine you want to apply all your intuition about music [more accurately, theory of sound, not music theory] to seismic signals. Well… unfortunately, we really do care about the timing of these signals. So instead of ditching all the magical techniques of linear algebra and transform analysis, we can pick a new set of waves and decompose in terms of those. I.e., we use a transform “midway” between the Fourier transform and the identity transform (doing nothing, just working with the raw signal).

One way to do this is to start with a wavelet: any waveform with zero average and finite “length”. Then, you take this mother wavelet, and you create child wavelets by stretching and/or shifting the mother wavelet. Then, you break up your signals in terms of the wavelets. (I think you pick wavelets based on what you want to find. For example, if you want to find sharp changes, you can pick a Haar wavelet, which is basically a family of rectangles. And then, you can pick wavelets based on their statistics so that the variances and higher order statistics vanish.)

My favorite book on Wavelets, and one of my personal favorite books, is A Wavelet Tour of Signal Processing: The Sparse Way by Mallat. It’s a bit mathematically challenging, but it’s such a fun read. One of the few books I actually own in print. And it’s one those cool fields in math where you basically just start with like pure math and end up with some incredibly practical results and algorithms.

Research:

My background is in control theory. I work on analyzing dynamical systems, specifically large-scale, complicated (typically people use the word “complex”, but I really mean complicated, because all the systems I work on evolve in real spaces) systems that evolve in time according to differential equations (e.g. electronic circuits, mechanical systems, power systems) or difference equations (e.g. sampled versions of the above). The goal of my research is to make just enough assumptions and prove it using calculus so future generations don’t have to do so much calculus…because you have to do so much calculus that not even a supercomputer can solve it.

PM me for more details since I’m not quite ready to dox myself 😆

Goddammit now I want to talk about wavelets and my research 😆

Do you know? Curious where folks pick this stuff up.

I do know that Maoists use it, but I think I picked it up when I read about some Black Panthers using it (I mean they probably were Maoists). And also I started doing this when some snarky shitlibs were like “oh you shouldn’t say ‘America’ because Central America is ‘America’” so I’m just like “then I guess we’re doing this now” 😆.

I’m an anarchist so of course not a Maoist, but I absolutely do not disagree with Maoists about the particular issue of America not being a good thing. Sorry if I’m being a bit annoying but this stuff is super important me, i.e. it’s important to have a good understanding of recent history.

Healing is a right, not a privilege

Every AmeriKKKan politician and millions of brainwashed USians:

Unfortunately I have a terminal case of CBA (can’t be arsed)

Being “slightly less than servile to AmeriKKKan sensitivities while anarchist” is not being “a tankie”.

If you don’t mind sharing, did you have to pay the exit tax? Actually, what was your way out?

No I’m pretty sure you’re a liberal, right? We probably do not agree almost at all. See this video for more information.

Oh well

Removed by mod

Fine, just do Ctrl+F, replace each instance of AmeriKKKa with {insert preferred term for the United States}, and move on with your life. Like I’m not even trying to get you to say it, I’m just saying it. It’s almost like you have a problem with what I’m saying and not just how I’m saying it…

Yeah I hope I get the mental help I obviously need…oh no wait I’m in the US so no I won’t

A: It completely undercuts the seriousness of your comment and makes the whole thing come off as a tirade by an edgy teenager.

So you disagree with the tone and not what I’m saying? Because if so, that sounds like a “you” problem, i.e. you’re more interested in the tone of a message than its content.

B: Jokes don’t get funnier every time you repeat them, it was mid the first time and eye roll worthy by the 3rd.

It’s not a joke and it’s not supposed to be funny. I genuinely hate the USA and everything it stands for.

My comment was in response to a comment about AmeriKKKans having “Stockholm Syndrome”, which as it turns out is not a real or valuable diagnosis. However, I do not disagree with the implied critique of AmeriKKKan people as being feckless and servile people.

Does anyone really need to live? What you need is to be producing value for your company!

/S

AmeriKKKa is a settler-colonialist project, and the entity and its defenders deserve zero respect. I mentioned AmeriKKKans because the person I replied to used Stockholm Syndrome to critique AmeriKKKans on a post critiquing the AmeriKKKan healthcare system, so critiquing AmeriKKKa is relevant here. And I don’t like spelling AmeriKKKa as part of USA correctly because (1) places like Central America and South America should be distinguished from the United States of AmeriKKKa, and (2) it offends the people who need to be offended, i.e. people who still feel affinity for the AmeriKKKan project and people who tone-police others who are just brutally honest in speaking their minds.

You are literally posting from an anarchist Lemmy instance, why TF is this controversial to you?

Reminder that the term Stockholm Syndrome was coined to blame victims for being rightly more afraid of the police than their captors:

In [Jess Hill’s] 2019 treatise on domestic violence See What You Made Me Do, Australian journalist Jess Hill described the syndrome as a “dubious pathology with no diagnostic criteria”, and stated that it is “riddled with misogyny and founded on a lie”; she also noted that a 2008 literature review revealed “most diagnoses [of Stockholm syndrome] are made by the media, not by psychologists or psychiatrists.” In particular, Hill’s analysis revealed that Stockholm authorities, responded to the robbery in a way that put the hostages at greater risk from the police than from their captors (hostage Kristin Enmark, who during the siege was granted a telephone call with Swedish Prime Minister Olof Palme, reported that Palme told her that the government would not negotiate with criminals); as well, she observed that Bejerot’s diagnosis of Enmark was made without ever having spoken to her.

Otherwise, we probably agree that AmeriKKKans are a feckless, servile people.

Okay Pooh, based answer but this isn’t World History homework, this is English homework, so I actually need you to spell “murderer” specifically please