Questions tagged [interpolation]

Questions on the interpolation functions in Mathematica (InterpolatingFunction[], Interpolation[], ListInterpolation[], FunctionInterpolation[], InterpolatingPolynomial[], etc.)

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25 views

Numerically solve a non-differential equation with InterpolatingFunction as output

I have some a function that I need to solve numerically over an entire domain (Ideally I would like an InterpolatingFunction object as output), which does not include any derivatives. I have found a ...
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1answer
38 views

Manipulating lists based on conditionals and 3D plotting the smooth surface that bounds a list of points

First of all I want to create a list of evenly spaceed points in a cubic region in $\mathbb{R}^3$. Then I want to keep the points in this list which satisfy a certain condition, i.e. a function that ...
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0answers
26 views

ParallelTable of NIntegrate of an Interpolating Function

I construct a 2D interpolating function using the following data (MWE): ...
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23 views

Why ListInterpolation does not allow InterpolationOrder greater than 2 in the “y” direction?

The order is always reduced to 2 in the "y" direction; I would want a better approximation to my data. Independent of the method (spline or hermite), I can choose any order for the "x&...
4
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1answer
63 views

Plotting an InterpolatingFunction outside its domain doesn't raise error messages

Let's make an InterpolatingFunction: if = Interpolation[Transpose[{#, Sin@#} &@Range[0, 4, 0.1]]]; As expected, evaluating ...
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1answer
44 views

3D interpolation providing derivatives

I am trying to interpolate 3D data by also providing the 1st order derivaives in all directions, i.e., besides (x,y,z,f), I also have df/dx, df/dy and df/dz. According to the documentation I should do ...
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2answers
70 views

Finding the arc length of a region defined implicitly with an interpolated function

I begin by defining an interpolation of some data I have stored at this link for brevity. The interpolating function is a function of two variables, x and ...
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1answer
55 views

What is the meaning/significance/importance of 'order of interpolation' used in Mathematica? [closed]

You can find details here - https://reference.wolfram.com/language/ref/InterpolationOrder.html.
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2answers
122 views

PeriodicInterpolation does not work in ElementMeshInterpolation

I want to use ElementMeshInterpolation to generate interpolation function with periodic boundary condition. I use below data as an example ...
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1answer
68 views
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1answer
66 views

Convert list of InterpolatingFunctions to data [closed]

If I have g which is a list of Interpolation functions such (I cannot copy the interpolation functions for some reason): g= How ...
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0answers
72 views

An issue with ParallelTable

Consider a function function[x_,y_,method_,distr_]:=NIntegrate[distr[x,y,z,t],{z,zmin[x,y],zmax[x,y]},{t,tmin[z,x,y],tmax[z,x,y]},Method->method] Here, ...
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3answers
153 views

How can I interpolate time-series data?

I fetch financial data like this: data = FinancialData["SBUX", "Close", {{2013, 1, 1}, {2013, 8, 1}, "Week"}, "Value"]; ...
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2answers
96 views

Efficient sinc interpolation of a list

I'm looking for an efficient way to construct a sinc interpolation i.e. an interpolating function of a list of numbers in the form of a Fourier series with a chosen maximum frequency. The input list ...
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0answers
31 views

InterpolatingPolynomial: magnitude of coeffictions

I have a list of the type {{x,y},f} and want to get an InterpolatingPolynomial for that list. The x values all run between 1.3 and 2, the y values between 0 and 1. ...
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49 views

ListLinePlot's Interpolation method

I Interpolated some oscillating data points using ListLinePlot[] , and set the InterpolatingOrder->10 . This gives a nice ...
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4answers
123 views

How to integrate the interpolated data over the region in which it is non-zero?

Consider some toy-function which I then interpolate: ...
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1answer
66 views

Derivative of a 3D Interpolated function

I cannot get the partial derivative of a set of data. I managed to get the accurate interpolation, but I cannot evaluate its derivatives. Here are my details: ...
3
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1answer
74 views

InverseFunction and Plot them

I'm trying plot an inverse function ...
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2answers
123 views

Detrending or removing linear trend from 2D data

I have some data that when plotted I get an inclined graph, as described: ...
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0answers
45 views

Interpolation for different Parameters

I am rather new to Mathematica and I tried to find a solution for my Problem on my own, also looking through this site and the suggested Similar Questions, but I at least could not make out that my ...
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2answers
86 views

Solve an interpolating function [duplicate]

I have been working with interpolating functions recently and have two functions as a result of an interpolation of two co-ordinate lists. The code I used: ...
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4answers
374 views

Nested optimization problem - Function approximation

I need to maximize the following function (the input to NMaximize below) ...
2
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1answer
40 views

Lagrange polynomials

I need to plot the 9 Lagrange polynomials associated to the points {−4, −3, −2, −1, 0, 1, 2, 3, 4} all on the same axis. So my attempt: ` ...
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1answer
99 views

ElementMeshInterpolation on a BoundaryMesh

It appears as though ElementMeshInterpolation does not play nice with the element meshes produced by BoundaryMesh ...
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1answer
32 views

problem in Interpolation

I made a force diagram into a matrix. How can I have find a value in y for a number in x? I know for 0.1 for example the force becomes 500, or for 0.3 it becomes -500 How do I know how much it will be ...
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4answers
415 views

Interpolation on an unstructured mesh

(Edit: This question is about making a mesh on a 2D surface to work with a 3D surface look at ElementMeshInterpolation on a BoundaryMesh ) I have experimental data in the form of { {x1, y1, z1}, {x2, ...
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1answer
71 views

Matrix as the discretization of a function $u$ over a rectangle in 3D, how to integrate fast along the axes

I have a function $u$ from 3D to 1D approximated in a list uu and I want to calculate e.g. $$\int_0^1 x\cdot u(x,y,z)dx$$ or $$\int_0^1\int_0^1\int_0^1 u(x,y,z)...
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3answers
112 views

Make an InterpolatingFunction periodic

Interpolation can make an InterpolatingFunction periodic with the option ...
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1answer
134 views

Interpolation not working

This is probably a very silly question but I am trying to use Interpolation for the following data: ...
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1answer
28 views

Derivative of predictor function

Given some data dat, we would like to generate a predictor function. Therefore we use ...
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1answer
56 views

How to plot in xz-plane?

Using the following code I am able to plot x(t) and z(t) values with respect to time. But how to do a plot with x(t) values as x-axis and z(t) values as y-axis. Any suggestions please. ...
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1answer
58 views

Interpolation of points in 3D through a Fourier series

I have the following data ...
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2answers
76 views

Determining the analytical equation of an interpolating function [duplicate]

I have the following problem I have the following data ...
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2answers
59 views

Cut an interpolating function

I have some data ...
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1answer
44 views
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1answer
53 views

NDSolve of a 3-D function from interpolated data

I have a 3-D data set (linked in the comment below) obtained via numerical integration. I would like to generate an interpolating function, and then use this function to numerically solve an ODE. For ...
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2answers
46 views

Access to Interpolation expression of Mathematica's Interpolate command

To reproduce fits which have been done in the framework of a standard, I was reviewing the Interpolation engine of Mathematica (for InterpolationOrder -> 3) to get more information about the ...
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1answer
52 views

Interpolate points in a three-dimensional space with Mathematica [closed]

I have the following set of points in a 3D space ...
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1answer
44 views

Find barycenter of spectral data

I am trying to find the barycenter of some spectra using numerical integration. I tried to find the wavelength for which the integral splits the spectrum in two equal areas, but the result seems wrong....
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1answer
67 views

What is the syntax for using Reap and Sow and WhenEvent with derivative = 0 with interpolating function?

I have a system of three ODEs. This system oscillates. I need to determine the frequency of each of the three solutions. My file. You can download and modify this. I'm new to Mathematica and I know ...
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1answer
54 views

Finite Difference Derivative on Extrapolated Data

I have an (in reality complex) function on a grid, which approximately vanishes at the boundaries of the grid, and which I want to project onto a larger grid. Example: ...
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3answers
439 views

Finding a set of line segments to fit noisy data

Looking for a methodology to choose line segments that are a rough fit to a given set of data. In this example, the data are {x,y} pairs. For example, if the data looked like what is shown on the ...
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0answers
67 views
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2answers
105 views

Super Slow Manipulate with Heat Equation - - Assumption, and Interpolate

Aim: solve coupled heat equation with cubic source, use DensityPlot and observe how system will react to changes in parameter(like kand ...
0
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1answer
102 views

Newton's divided differences iteration

I am trying to write a program that forms the interpolation polynomial for a given function on a given interval for any number of data points n. I wish to write a formula that will compute all of the ...
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1answer
65 views

Smoothing a function after interpolation + trying to fit 3D data into model without accurate prior knowledge

I have a physical problem simulation that generates this data set in the two cylindrical coordinates $(r,z)$ (doesn't include $\phi$ dependence). The data set (see .wdx file) is in the flattened form $...
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0answers
60 views

linear interpolation error [closed]

I have two set of data for pressure and energy density and I used a linear interpolation to apply the data as a function in terms of each other. ...
0
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1answer
163 views

How to calculate the expression of error truncation function?

We already know that some node information of function f(x) is shown in the table below: $$\begin{array}{|c|c|c|c|} \hline x_{i} & 0 & 1 & 2 \\ \hline f\...
2
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1answer
50 views

Multidimensional fit and interpolation for scattered unstructured data

I have data structured like {{{i,j},f(i,j)},...}}}. In my actual data the relationship between f(i,j) and ...

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