Laplace transform marathon: 👉 kzread.info/dash/bejne/mKii0q-YgrKWesY.html

Programmers: *TRIGGERED*

@blackpenredpen

7 жыл бұрын

lol!

@blank0s162

7 жыл бұрын

Can confirm

@blank0s162

7 жыл бұрын

REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

@3dflux

7 жыл бұрын

AxeSkull , hahaha! I was thinking that exact sentiment. I was happy to learn about convolution though.

@Periiapsis

6 жыл бұрын

print(conv(1,1))

Every computer scientist watching this video is currently cringing

@soulsilversnorlax1336

7 жыл бұрын

I was just thinking "In programming, 1 * 1 = 1 and 1 • 1 is usually undefined."

@yosefmacgruber1920

6 жыл бұрын

+blackpenredpen Use proper symbols. Is contextual-based definition supposed to be so obvious? I think not. I confirm the "computer scientist" cringing that I also felt.

@yosefmacgruber1920

6 жыл бұрын

+Fest Blats In Applesoft Basic, it can also be expressed as *_LET_* A=A+1. Thus the "LET" is understood if it was omitted. I think some programming languages deal with variable value assignment with something such as A =: A + 1 or use == as an additional symbol, so that variable assignment value and tests of equality, are not overloading the same symbol. BTW, Applesoft BASIC does not declare variable types, as variables do not exist until their first value assignment. An undefined variable gives the value of 0, which is likely not valid in many other programming languages, but could be treated as a program error, that halts execution. I think that an undefined variable may return the null string, in a text string calculation. Either that or TYPE MISMATCH ERROR. Having some experience with programming, I immediately recognize the programming context of a=a+1 as that is obviously not true in mathematics, well unless preceded by something such as LET A = ∞. But in programming, a comparison operation is meaningless, unless it is surrounded by a truth test, such as IF ... THEN... Or in Applesoft Basic, truth = 1 thus PRINT (a=a+1)+0 evaluates to a value of 0. Or if I wanted to do temporary change to a program line of code, for testing purposes, I might type something like IF 1 THEN ... to do a forced-conditional branch. So A=A+1 by itself, with no reason to do the math, is interpreted as a variable value assignment, with the "LET" being understood if it was omitted. Applesoft Basic does not recognize the symbol =: as the : character is the command separator, if multiple commands are used on the same program line. There is no ELSE command word to the IF...THEN, nor any BEGIN nor END coding blocks as in Pascal, thus multiple commands may have to be included on the same line, as the "ELSE" (it was a false-result comparison) simply drops to the next program line. Thus, if too many commands follow the IF...THEN being true, the last command will often have to be GOTO or GOSUB. BTW, in C+, wouldn't it be expressed as A+ to increment the variable A? But BASIC (Beginner's All-purpose Symbolic Instruction Code) seems to lack any increment and decrement commands. Hence the A=A+1 often found within a loop structure. It may then test to see if A exceeds the loop count and exit the loop if so.

@mont8245

5 жыл бұрын

Not data scientists

@blockhet

4 жыл бұрын

Computer scientist should already know this.

first one is "wrong" too, can't dot product two scalars ;)

@blackpenredpen

7 жыл бұрын

lol, true!

@ffggddss

7 жыл бұрын

What looks like a scalar, can perfectly well be a 1-D vector, which makes this still correct. But then, we're using the same symbol to mean different mathematical objects on opposite sides of the equation.

@GSandSDS

7 жыл бұрын

I think it's just a matter of semantics. How is the dot and the star defined. And that's where the problems begin. For example: In germany (where I live) instead of the × the dot is also the official symbol for the multiplication of two scalars, and in many programming languages the * is the official sign. This is not a question of right or wrong but of convention.

@yosefmacgruber1920

6 жыл бұрын

But inconsistent usage of symbols, counts as "wrong" in my book. * still is the official multiplication symbol. There is no • character in basic ASCII upon which programming was based upon. Only modern computers have extended character sets, and even though, it still is not much used.

@TheDavidlloydjones

6 жыл бұрын

GSandSDS, This "just" a matter of semantics thing has always puzzled me. Semantics is about what the thing means. It doesn't get much more important than that, does it?

I came here to confirm that 1 * 1 = 1. I left with differential equation convolutions and the integral from 0 to t of dv. So 1 * 1 = t. Thanks destroying my entire conception of mathematics.

@SuHAibLOL

7 жыл бұрын

as soon as I saw the thumbnail I was like "lol it's gonna be a convolution"

@blackpenredpen

7 жыл бұрын

I will have a vid soon on 1*1*1*1

@patrickhodson8715

7 жыл бұрын

blackpenredpen is convolution commutative and/or associative?

@ffggddss

7 жыл бұрын

Look at the definition and work it out!

@rishabhdhiman9422

6 жыл бұрын

Its associative

Thank you. I have never heard of convolution before. However, in Computer Science, * is used for multiplication because of the keyboard. In group theory, * is an operation. And you can define * any way you want. Thanks for being clear about what you mean by *.

"... the star means convolution in differential equations." That symbol means lots of different things in different mathematical contexts. Convolution is just one of them. In almost every computer language, it's a binary operator, and means multiplication. In complex numbers, it's a unary operator (usually in raised position), and means complex conjugate. In group theory, and differential geometry, it has other meanings. Etc. And yes, in functional analysis (where differential equations may or may not be involved), it means convolution. It's a binary operator on two functions, whose result is one function. Also, when you stipulate that "*" means convolution, and you write "1*1," you haven't specified a name for the independent variable. It doesn't have to be t, unless you say so beforehand; although usually, the prior context will supply that. You can get around this notational difficulty using the lambda notation: 1*1 = t_λ(t) This RHS means, "the function whose value at t, is t." And on the LHS, "1" also stands for a function - the constant function whose value is 1. Welcome to the world of not-always-completely-rigorous mathematics!

@badhbhchadh

5 жыл бұрын

Actually, what he does is 1∗1. 1*1 is what he wrote in the title.

@Resursator

5 жыл бұрын

Ahh, these damn symbols.

@angelmendez-rivera351

4 жыл бұрын

ffggddss Mathematicians are terrible when it comes to semantics and notation.

@The_Aleph_Null

4 жыл бұрын

@@angelmendez-rivera351 programmers are worse

@danielchoi4490

2 жыл бұрын

@@The_Aleph_Null lol so true. A lot of programs are theoretically Turing complete. You only *need* one, but because people want to argue semantics there's so fucking many. And efficiency and purpose, but I will erroneously ignore those to support my argument.

In general, * usually just denotes a dummy binary operation

@blackpenredpen

7 жыл бұрын

It is! Especially in abstract algebra. But in diff eq, it is the convolution..

Clickbaited math-style

Oh my god.... Never heard of this. Lol

programmers, you're wrong, 1*1=1 is still wrong, why do u want to assign an int to an int? that doesnt make any sense, 1*1==1 is correct, or may i say true instead

@zumoss

4 жыл бұрын

i laughed

@pafnutiytheartist

4 жыл бұрын

Depends on the language. Some languages use = for comparation and := for assignment.

@imacds

4 жыл бұрын

1*1==1 is 1

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

I was expecting one of those silly series addition exploitations to make 1x1 equal -1/5 or something.

You know you're screwed when the literal name of the operation is "convolution"

I came here and know this after 3 years... Does this still work after the latest patch?

You should do this for linear algebra too

Btw, * is also a symbol for a binary operation in Abstract Algebra.

What about two functions f and g so that they are both equal to 1 for some variable t, is f (t) * g (t) = 1 possible?

Why does this convolution differs from that I've heard in the course of Signals and Systems?

I was asking this question some days before to see this, i'm impress

what is a t and where did it come from?

2:33 greatest jumpscare of 2019

Hopefully i learn this more depth

Why was I taught that convolution is defined by the integral on the entire real line, but you said it was from 0 to t?

When he asked, "What's 1 x 1?, I thought to myself, "I KNOW THIS!" I had no idea the answer would be so "convoluted" (Which I never heard of).

I was notvtriggered, but I must pointbout: Yes, the star (* or asterisk) means convolution in calculus. But in most computer languages, the * is the multiply operator because keyboards are laid out for text and math. So, in computers languages, we have functions that perform convolution or we have to do all the math with the basic math operators and loops. When we write papers, we can use Microsoft Equation and then of course we use dot (the product dot not the period) for multiply.

I've heard of convolution, but I'd never seen it given a symbol until now!

[0,t]?I remember that the interval used in convolution is (-∞,∞).I am taught that it should work in Real domain.

Thanks, but I really need the proof of the definition of the convolution theorem

can you do the proof of this ?

Kung-Fu-Lution !

Wow first time knowing this one But isnt the case now f(t)=1 and g(t)=1? if the result is t, doesnt that mean t can be anything? (cuz domain of f(t)=1 can be anything)

Somehow, somewhere in my heart, I feel this was all just an excuse to talk about convolution...

Programmer: My life was a lie

Normal human and other mathematicians:1*1=1 Blackpenredpen: 1*1=t Me:BrUh

Lol never expected that

@blackpenredpen

2 жыл бұрын

😆

You said 1 not a step function. A convolution does not strictly say t>0. Its a non causal signal but still. so this is only true if you mean that "1" is actually equal to 0 for t>0 and 1 for t>=0. and then your answer would be 0 for t=0

@angelmendez-rivera351

4 жыл бұрын

Mishchievious Badger That makes no sense. 1 is a constant function. There is no requirement for t > 0 in order for the integral to be equal to t. You speak gibberish.

@ANAboIik999

4 жыл бұрын

@@angelmendez-rivera351 actually the answer has to be infinity . Am i right ?

@angelmendez-rivera351

4 жыл бұрын

Vitya Kozatchenko Ni

@VargoViaty

4 жыл бұрын

@@angelmendez-rivera351 convolution ranges from -∞ to ∞, if he used a unit step function he could have trimmed the -∞ to 0 and the ∞ to t, since anything outside that boundary would be deprecated and the result would be the same. But he didn't use unit step functions, he used the constants 1, which are nonzero from -∞ to ∞, so it was wrong from him to do evaluate 1*1 from 0 to t

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

After taking diffeq, I knew the answer was t based off of title ;)

thanks a lot mannn,

is convolution and binary operation the same?

@angelmendez-rivera351

4 жыл бұрын

do not laugh again A convolution is *a* binary operation, but not every binary operation is a convolution. A binary operation is a class of operator, not an operator in itself.

Jeez, hate complicated math because variables just drop out of nowhere

You are the best ❤❤

This all seems very convoluted.

Why (0 to t) instead of (-inf to inf) ?

What is t?

where does the v come from? Both functions are functions of t, and v seems to come out of no where.

@blackpenredpen

7 жыл бұрын

Bigpapapolarbear it's just a dummy variable for integral purpose.

@srpenguinbr

6 жыл бұрын

you cannot integrate from something to t with respect to t. It could be any symbol.

@bro_vega_1412

4 жыл бұрын

Things of math always come out of nowhere.

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

so is 1 * 1 the identity function?

@angelmendez-rivera351

4 жыл бұрын

Yung Stew Yes

Well guess i have to write 1•1 now, even though i can do usual 1×1.

But 1.1 = 11/10 ¬= 1. ;)

I remember reading about convolutions on the dark web. I'm glad it isn't a made up dark web thing.

so doing multiplication in java has always been wrong , thanks my life is a lie

But here`s another question: wtf is actually the t? Is that mean that 1*1 is equal to literally everything?

@Macion-sm2ui

4 жыл бұрын

It's formula of function

Devs, close your eyes and pretend that you've seen NOTHING!!

For just 399$ yes I can

This must mean that t is 1. Change my mind.

But what is t?

This is too convoluted for me.

Superp sir

Terrance Howard wants to know your location.

now what is 1.2.3.4? its 1.2 times 3.4 so 4.08 i donno man dots are confusing

@Manisphesto

2 жыл бұрын

1.2 · 3.4 It's just more confusion.

NOOOO MICROSOFT EXCEL YOU HAVE LIED TO ME YOU HAD THE HIGH GROUND ALL ALONG!!!! 😱😱

This is convoluted.

This is assuming the 1 function is 0 if t

Notice that 2+2=2*2=2^2 Therefore we conclude that + = * = ^

Hmm... that looks more like the convolution of twice the heaviside step function, rather than the constant function 1 with itself. (which doesn't converge, obviously)

@angelmendez-rivera351

4 жыл бұрын

ImaginaryMdA Why would it not converge? The interval of integration has finite measure, and constant functions have no discontinuities or singularities.

@Tetration

4 жыл бұрын

Angel Mendez-Rivera Technically, the limits of integration for convolution is negative infinity to positive infinity. You’re really only allowed to use the 0 to t limits if both functions are 0 for t

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

What is the aplication of this?

@easymathematik

5 жыл бұрын

Making videos. Haha. No. U find convolution in different topics. This integral becomes important in solving differential equations by Laplace Transformation. There is also a discret version in theory of difference equations.

@VargoViaty

4 жыл бұрын

pretty late response but in electronics for example, convolution is widely used in signal processing (audio, radar, radio, whatever you want), it helps us understand how a system in the time domain will respond to any given input, and to also design systems that generate a specific output we want based on any input we feed it

@flaviodomingos1989

4 жыл бұрын

Ty for the answers

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

Lol I was stuck at this part 😂 thank you Allah I found you!!! 🙆🏻

Now, let t=1 and you're done 😆

I believe it can be looked at as 1^2 then by taking the square root= absolute value of 1 which is +1

@Joffrerap

4 жыл бұрын

Wat

Uhhh just use your variable as 1 instead of t and you're good

In computer keyboard * is used for multiply

but what if t = 1

actually who tf started the wrong use of * as multiplication?!!

@obinnanwakwue5735

6 жыл бұрын

TM Fan We don't have \cdot on our keyboard, so...

@tmfan3888

6 жыл бұрын

keyboard manufacturers should have put the real multiply and division signs on keyboards

@TheF4talgamer

5 жыл бұрын

Seems like you dont know programming

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

@tmfan3888

2 жыл бұрын

@@chandranichaki9580 wrong comment

What's t?

what is t?!😅cant we find it

@Joffrerap

4 жыл бұрын

* operation is (in this video) only defined between functions. If you want to make sense of 1*1, you have to interpret 1 as a function: 1 is the function that associate 1 to any t ( it is a constant). 1*1 is the function that associate t to any t . We can t find t, it is a variable.

So what's t?

Imagine if he had just said it was 1 and the video was 2 seconds long.

I thought that the * sign was for internal operations when you define a vector space

@The_Aleph_Null

4 жыл бұрын

Isn't that but on brackets instead of less signs?

Obviously 1*1=2 if your Terrence Howard

i thought its 1apr but its 29apr

Autocorrelation lol .. * can be any binary operation..multiplication is binary too

You meant 1∗1.

So 1*1 is undefined, because both are constants and are invariable regardless of t.

Imagine saiyng 1*1=X

Or, if we were considering (*) as the Dirichlet convolution, then 1*1=d, where d(n) is the divisor counting function. I know it is unrelated, but I like analytic number theory haha :)

@blackpenredpen

7 жыл бұрын

Jack Johnson lol! The * notation is very useful!

Also this is strange definition of convolution. Shouldn't it be integral over whole space? Integrating over (0,t) seems strange. Maybe it's some alternative definition made in a way it still doesn't depend on order of convoluted functions and it gives us finite values for functions that are not in L1 so it might have more applications. But now when I look at it I'd just call it convolution of indicator of set (0,infinity) with another indicator of set (0,infinity) and then it's convolution in standard sense so it's like you multiply both f and g by indicator of (0,infinity) and then computing convolution of these new functions.

@ffggddss

7 жыл бұрын

It's the same as the difference between a definite and indefinite integral. Integrating over the entire interval would be a definite integral, and would result in a number. Integrating over a variable interval results in a function.

@SultanLaxeby

7 жыл бұрын

This is the Laplace convolution. It is turned into multiplication under Laplace transform. The integral over the whole space would be the Fourier convolution (how I like to call it, because it's turned into multiplication under Fourier transform). There are even more convolutions, corresponding to other transformations (e. g. Mellin, Dirichlet, Cauchy)

@TheMasterfulcreator

5 жыл бұрын

@@ffggddss It doesn't result in a number for general functions f and g even if you integrate over the whole space. This was an artifact of the functions f and g being constant in this case.

@ffggddss

5 жыл бұрын

@@TheMasterfulcreator If you replace the limits of integration with constants, yes, the "t" will still come through the integration over v. If you integrate over the whole real line; i.e., if those constants are (-∞,∞); the integral will, in this case, diverge to ∞. I think Konrad is right - this *is* a little weird, to integrate from 0 to t, with "t" also appearing in the integrand. I believe you'd normally choose a fixed interval of integration, with "t" still in there, as shown. Fred

@TheMasterfulcreator

5 жыл бұрын

@@ffggddss You're right for this particular case. I was pointing out the fact that in general there are choices of f and g so that when integrating over the whole space, you will not have a number as a result (because like you said t will come through the integration over v). You will have a function of t. I'm not sure what you mean by it being weird unless you're just referring to how it's not the normal definition of convolution.

1x1?

In the end you need to multiplay result by unit step function.

Wait until you use cross products.

Awesome. I love convolution

You are making Mathematics just complex for others.

1*1=귀요미

Y'know, it could be 1, if you choose t=1.

@Joffrerap

4 жыл бұрын

1(1)*1(1)=1

@NStripleseven

4 жыл бұрын

maxime weill Exactly

@Joffrerap

4 жыл бұрын

@@NStripleseven just wanted to write it because it looks funny. :)

@chandranichaki9580

2 жыл бұрын

kzread.info/dash/bejne/h6SqzZOYfZOoXc4.html

Of course 1 * 1 = 1 is wrong, you are assigning a rvalue to another rvalue, how does that make sense. So the correction should be 1 * 1 == 1 jk

{1} x {1} = {1, 1}

1 * 1 = 1 1 ∗ 1 = t

But t = 1 isnt it

My life is a lie.

I program in python and when you multiply, the syntax is "*". The programmer in me kicked in and I was confused but then I understood... Thank you!

Yeah but wtf is t

Funny that math has different signs in different languages. Here, we write 1,5 but in America they write 1.5. Both are correct, but not everywhere. We use the dot as a thousand divider, so we can write 15.500,30 when others would write 15’500.30. Weird.

@sowndolphin5386

2 жыл бұрын

we would write 15.500 too