# Questions tagged [extrapolation]

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

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### 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 ...
• 3,003
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### 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 ...
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### extrapolation/interpolation in fmincg.m

Can you tell me these equations come from where in MATLAB fmincg.m? ...
1 vote
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### 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. ...
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### 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 ...
• 965
1 vote
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### 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 ...
• 15
1 vote
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 ...
• 608
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### 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 ...
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### 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 ...
• 647
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### 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 ...
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1 vote
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 ...