Questions tagged [extrapolation]

Extrapolation is a method of constructing new data points outside the range of a discrete set of known data points.

Filter by
Sorted by
Tagged with
4 votes
0 answers
60 views

Pade-like approximation, but force poles to be negative

Are there techniques to form a Pade approximation (or Pade-like approximation), except force the poles of the rational function to be negative? I am trying to use Pade approximations to extrapolate a ...
user avatar
  • 3,003
0 votes
0 answers
45 views

How to solve for underlying function from discrete data set containing integral of that function

New to Computational Science, I hope I'm on the right exchange network for this question. I have a time series data set that contains the sum of a source data set representing an exponential decay ...
user avatar
0 votes
0 answers
47 views

extrapolation/interpolation in fmincg.m

Can you tell me these equations come from where in MATLAB fmincg.m? ...
user avatar
1 vote
0 answers
60 views

Extrapolating to non-fluid cells (for Shallow Water Equations), for a shore/beach?

The water height $h$ and 2d velocity field $(u,w)$ are "extrapolated to non-fluid-cells, i.e., setting $h$ equal to the value in the nearest fluid cell." [Bridson] I'm using finite differences. ...
user avatar
4 votes
0 answers
88 views

Extrapolation after successive finite element refinement

I wish to compute a certain function $\lambda$ (in my case an eigenvalue of the Laplacian) to a certain accuracy, which I wish to guarantee, if possible. I started with a finite element method. I know ...
user avatar
1 vote
1 answer
85 views

Using two reference values for a scalar variable: What's the name of this type of problem?

I don't really know where to ask this one... In fact, I am not sure I can define it properly. Here goes... Let's say I take measurements. In order to "normalize" these measurements, I divide their ...
user avatar
  • 15
1 vote
0 answers
104 views

Application of vector extrapolation methods to convergence to a steady state solution

I'm working on a fluid solver using dual-time stepping and everything works really well, except the convergence in pseudo-time is slow. I'd like to accelerate the convergence. I know multigrid methods ...
user avatar
  • 608
2 votes
1 answer
257 views

FVM - virtual node discretisation

I have come across the paper titled: A monolithic fluid structure interaction algorithm ... For a 1D grid, at the boundaries the paper uses virtual nodes $x_{0}$ and $x_{N+1}$ (page 372) and for ...
user avatar
  • 169
28 votes
1 answer
27k views

What is the preferred and efficient approach for interpolating multidimensional data?

What is the preferred and efficient approach for interpolating multidimensional data? Things I'm worried about: performance and memory for construction, single/batch evaluation handling dimensions ...
user avatar
13 votes
3 answers
310 views

Computing slightly oscillatory series to high precision?

Suppose I have the following interesting function: $$ f(x) = \sum_{k\geq1} \frac{\cos k x}{k^2(2-\cos kx)}. $$ It has some unpleasant properties, like its derivative not being continous at rational ...
user avatar
  • 11.4k
1 vote
0 answers
32 views

Combining trend estimation and constrained Marquart fit

This title certainly needs some clarification: I need to compute parameters $a_i$ for a helper function $f(\vec{a};k)$ (for grid interpolation) which is fitted to a number of values $y_k$ which are ...
user avatar
  • 1,109