Extrapolation Definition and 29 Threads

Studying delta sequences and am wondering if ##\phi_n(x)## is a delta sequence (it resembles and validates the sifting property), will ##\phi_n(x - a)## or ##\phi_n(whatever)## respect the sifting property ? I think I get confused in the semantics, because reading my textbook, I get the...

Hi guys, I was learning machine learning and I found something a bit confusing. When I studied physics I saw the method of least squares to find the best parameters for the given data, in this case we assume we know the equation and we just minimize the error. So if it is a straight line model...

The intense gravity near the event horizon causes complementary particles to pop into existence spontaneously. As local space-time is continuous through the EV, the same would be happening just inside the EV, only more so as the gravity field and gradient is greater. So near the singularity...

I got something like this, but I'm not sure it is correct, because if it has the same order of convergence as trapezoidal rule which is 2, it should yield the same result as trapezoidal rule but mine doesn't (?). For example sin(x) for [0,1], n with trapezoidal rule = 0.420735... With my own...

Hi, Originally, the absolute temperature was thought to be around -273 Celsius around 1750 and it was the result extrapolation of of ideal gas law as shown below. I find it hard to phrase my question. But the question is how come they were so confident that the relationship between the volume...

Summary: The universe is expanding, so at one point in the past it must have been all concentrated into a single point. But is this really an accurate observation? Hi, This is my second probably naive question that's been on my mind as a lay-scientist for a long time (the other will hopefully...

hi can you tell me these equations: A = 6*(f2-f3)/z3+3*(d2+d3); % cubic fit B = 3*(f3-f2)-z3*(d3+2*d2); z2 = (sqrt(B*B-A*d2*z3*z3)-B)/A; % numerical error in MATLAB fmincg.m...

Hello. I have a question about how close (in time) the Hot Big Bang theories formulated before 1980 could be reliably extrapolated to T zero. In his book... https://en.wikipedia.org/wiki/The_Inflationary_Universe ...Alan Guth recounts a lecture by Robert Dicke in 1978 which set the benchmark...

Hi, Could you recommend a book/essay/anything else about the philosophical approach of scientific extrapolation?

Let A be a random n×n matrix, x = (1,1,...,1)⊤ be an n-vector of ones and b = Ax be the right-hand side vector. As in class, let z = (zj) ∈ Rn be the result of solving the system Ax = b in finite precision using the backslash command. To measure the error between x and z, we let δ= max |xj−zj|...

Trying to understand what is going on here, and how this technique removes the dependence of sample rate from the solution.

Hello, I am writing a program for a two dimensional look up table. The idea is that the user will enter values for x and y and the program will look up the corresponding output value from the table. For example, consider the table shown below. For this table, if the user enters x = 2 and y...

Hi, Please note: this is not a homework question! It is a real world problem I am trying to solve. I have some values in mA and tonnes which I need to extrapolate but they are not linear. I know it the mA curve drops off the higher the tonne values go. I have plotted the values in excel...

On a stationary, non-periodic signal (black) a smooth causal filter is calculated (green/red). It is sampled discretely (every distance unit of 1 on the X-axis). My goal is to find which "path" it is "travelling" on so I can extrapolate the current shape until it is completed (reaches a...

Homework Statement [/B] use richardson extrapolation to estimate the first derivative y=ln(x), x=5 using steps of 2, 1, 0.5. Four decimal points. obtain true relative error for the last estimate and comment on its value. Homework Equations [/B] deriv ln(x)=1/xThe Attempt at a Solution I know...

Homework Statement Homework Equations Given above The Attempt at a Solution I used polyfit, but my mean swuare errors are way bigger than they should be- don't see what is wrong with my code! My code is ugly btw, my apologies. %Hw 7 clear all close all y3=[1960; 1965; 1970; 1975; 1980...

Hi could anyone give me pointer as to where to go with part iii please?

Construct extrapolation table with optimal rates of convergence Homework Statement Let S be a cubic spline interpolant that approximates a function f on the given nodes x_{0},x_{1},...,x_{n} with the boundary conditions: S''(x_{0})=0 and S'(x_{n})=f'(x_{n}). Use S to estimate f(0.1234567)...

Hey, I was hoping someone could help me with this question I can't get at all. If $$\phi{h}=L-c_1h^{\frac{1}{2}}-c_2h^{\frac{2}{2}}-c_3h^{\frac{3}{2}}-...$$ , then what combination of $$\phi{h}$$ and $$\phi(\frac{h}{2})$$ should give a more accurate estimate of L. Thanks for any help.

From Randy Blythe's Yahoo Answers Question: Use Richardson’s extrapolation, using a centred difference scheme for the initial estimates, to estimate the first derivative of y=(x^3)sinx at x=2 with step sizes h1=0.5 and h2=0.25. Calculate the actual derivative and the percentage error

Hi, I need to know how one can check space and time convergence using Richardson Extrapolation. Does anyone know any good references. I have a slight idea... the thing I am wondering about is how using this method can eliminate the need for further simulations using smaller time steps or a...

Can anyone explain why we humans have the innate ability to extrapolate 3-dimensional images from 2-dimensional images. I am not interested in how it works (i.e., how the brain accomplishes this feat). Instead, I would like to know why it was so important in the evolutionary process. In other...

Hello everyone, I did a quick search but could not find this in the forums. I have quite a basic situation. I have been gathering data points from an experiment and was able to fit an exponential curve of best fit to it. What I want to do is approximate some values between my data points...

I'm working on some physics lab homework and one particular graph is obnoxious. It's hard to tell whether it's intended as a compound curve, or if it's just a piss-poor sketch. I've contacted my professor but he hasn't responded for days, and it's due tomorrow. If I'm not mistaken, the...

Today I have been traveling across the night sky with Google Earth a bit. As always I'm surprised about how inspiring the cosmos is for thinking about physics. But I've always been quite skeptical about the big bang theory. Nowadays we're unable to simulate even a single hadron. And the...

Hi, I need to extrapolate vector v_{-1} from v_{0}, v_{1} and v_{2} (see attached pic), so that if v_{2} is on the right/left (2D case for simplicity) of v_{1}-v_{0}, v_{-1} would also be on the right/left. My initial solution was like this: v_{2} - v_{1} = v_{1} - v_{0} + dv, v_{1} - v_{0}...

Hi, I've a table of data in the following format: x--> 0.1 3.767 4.395 5.0223 y 0.1 | 1 1.5 2.0 2.0---->z 0.6764 | 1 2.0 2.2 3.599-->z 1.10146 | 2 2.2 2.5 3.686-->z 1.3855 | 2.5...

Could someone help me understand why interpolation rather than extrapolation should be used for calibration curves (with the exception of Standard additions). I know that extrapolation is less precise, but the book I've got doesn't over any more than that, and I think I need a little more detail...

Hi, Is there a general extrapolation formula (or other *simple* quantitative technique) for projecting values in a given series? I have these numbers in a certain series sequence: x=1, y=-3.80, x=2, y=-4.15, x=3, y=-4.47, x=4, y=-4.77, x=5, y=-5.05, x=6, y=-5.27, -5.40 Question is...