Nonlinear Least Squares

  Рет қаралды 44,491

Postcard Professor

Postcard Professor

Күн бұрын

Finding the line of best fit using the Nonlinear Least Squares method.
Covers a general function, derivation through Taylor Series.

Пікірлер: 29
@joseguerrero4
@joseguerrero4 2 жыл бұрын
You explanined in 10 min what my proffesor could't in two weeks
@morrismbuba763
@morrismbuba763 3 жыл бұрын
What a good explanation? Really got the point Prof.
@kupo871
@kupo871 5 жыл бұрын
Love the videos!
@gththcoc6010
@gththcoc6010 2 жыл бұрын
thank you man, that was an excellent explanation
@SalehGoodarzian
@SalehGoodarzian Жыл бұрын
Thank you for your detailed explanation of this method. After learning this method, I tried to write a code to do this example that you introduced here. As you rightly mentioned, initial guess is very important, particularly for c2. By looking at the data, we can have an idea of c2, that is related to the period of the cosine curve. If c2 is guessed too low or too high, the algorithm won't converge, it must be close to the true value...Thank you again for your great video. Educational, detailed, and very helpful.
@rishabhsangal5155
@rishabhsangal5155 3 жыл бұрын
This was really helpful sir. Thank you :-)
@elshaday9860
@elshaday9860 3 жыл бұрын
That was very helpful ; Thankyou very much,,,
@ParniaSh
@ParniaSh 3 жыл бұрын
Well explained! Thanks
@inigomeniego4906
@inigomeniego4906 4 жыл бұрын
Really cool!
@nmana9759
@nmana9759 3 жыл бұрын
Thank you so much! Can you please explain more about Gauss-Newton and Levenberg-Marquardt algorithms?
@machotravis
@machotravis 3 жыл бұрын
Thank you!!
@FreeThiinker
@FreeThiinker 5 жыл бұрын
You are Amazing !
@gabrielomorotionmwan6994
@gabrielomorotionmwan6994 4 жыл бұрын
ZERO-X please prof. How do I get the real value of c from the calculated changes in c. Will I add or subtract
@alb2935
@alb2935 3 жыл бұрын
Can you do this for a function with 2 variables e.g f(x,y;a,b) and g(x,y;c,d)
@konstantinmetodiev6888
@konstantinmetodiev6888 3 жыл бұрын
How do you make initial guess for the Ci prime vector (3:40)? Do these values affect the solution convergence? Thank you.
@PostcardProfessor
@PostcardProfessor 3 жыл бұрын
If you have a poorly behaved system, it's definitely possible for the initial guess to affect convergence. The simplest method of guessing good initial values is to do a brute force grid search over possible values, then choose a vector that results in a low residual as your starting guess. This method may prove intractable for systems with large numbers of parameters.
@haniffshazwanss5720
@haniffshazwanss5720 4 жыл бұрын
hey there. great video. just wondering how many parameters should we put? does it really matter no matter how many parameter we put in?
@PostcardProfessor
@PostcardProfessor 4 жыл бұрын
The more parameters, the more computationally expensive it is, but the method will work with any number of parameters. Ideally, you use as few as possible to get a good fit.
@Guide4Ever
@Guide4Ever 4 жыл бұрын
You have y(x) yet x is never in equation on the right side ?
@inigomeniego4906
@inigomeniego4906 4 жыл бұрын
I think he called it "t" later on, he got confused
@lucashyvarinen246
@lucashyvarinen246 Ай бұрын
how does iteration work for this?
@matthewjames7513
@matthewjames7513 2 жыл бұрын
I'm not sure if this is a typo but you write "t" instead of "x" consistently throughout the video.
@johnyoung9483
@johnyoung9483 3 жыл бұрын
Nice Aggie Ring! Thanks & Gig em AERO 23'
@gameggh6702
@gameggh6702 4 жыл бұрын
Is c1,c2 and c3 are known variable?
@rvoros
@rvoros 4 жыл бұрын
c1, c2, c3 are unknown, we have an initial guess for them then we iteratively improve c1, c2, c3 by adding dc1, dc2, dc3. The notation could be more elaborate by giving them an iteration index in the superscript
@hayatullah3135
@hayatullah3135 4 жыл бұрын
@@rvoros what is dc1, dc2 etc?? i mean how much change should be added to the previous parameter..
@mehmedhezenci722
@mehmedhezenci722 4 жыл бұрын
İf you know these variables, you cannot fit curve. Because , you will have one curve
@Etothe2iPi
@Etothe2iPi 2 жыл бұрын
1:16 x not t.
@samuelkushnir2639
@samuelkushnir2639 3 жыл бұрын
isn't this just gradient descent?
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