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

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12
votes
4answers
460 views

Quirk in VertexColors interpolation when displaying Polygon

When using VertexColors, the docs state: The interior of the polygon is colored by interpolating between the colors specified by ...
3
votes
3answers
3k views

Retrieve values of InterpolatingFunction

While analyzing a large system of ODE's, I defined a particular ratio p, which contains some variables that are represented by ...
1
vote
1answer
104 views

Interpolation of a NURBS curve

Known that NQ=P where N is the Bspline basis function, Q is the control point that we wish to locate, P is the data points given ( the curve must pass through it) is there any way to modify the "N" ...
0
votes
0answers
31 views

Multivariate interpolation [on hold]

I need to interpolate a function of 5 variables. I have 72 values of this function. f(12, 0, 50, 1, 0) = 3.28, f(12, 0, 50, 1, 50) = 3.35, etc. Do you know which ...
0
votes
0answers
17 views

Question regarding derivation of Interpolation functions [duplicate]

I am new to Mathematica. Can someone explain what is the difference between the second and third input (54 and 59) in following example (got from Mathematica site). In[52]:= ysol = ...
17
votes
1answer
452 views

How to fix broken InterpolatingFunction?

Fixed in Version 9 I have an InterpolatingFunction based on irregularly-gridded data, like this: ...
0
votes
0answers
39 views
0
votes
1answer
84 views

Many NSolves to interpolating function

I have an expression of the form: expr = TerribleNumericalFunction[U[p]] == SimpleFunction[p] The Simple function is a ...
6
votes
1answer
107 views

Kernel Crash while using “ValuesOnGrid” method of InterpolatingFunction

I was experiencing some kernel crash while using "ValuesOnGrid" method of an InterpolatingFunction returned by ...
3
votes
0answers
82 views
5
votes
2answers
156 views

Solve for x given an interpolation function, y

Given a list of data, lst={{x1,y2},{x2,y2},...,{xn,yn}} and the interpolation function fun, y=Interpolation[lst] which ...
21
votes
4answers
563 views

Arbitrary precision spline interpolation

The current implementation of Interpolation does not allow arbitrary precision spline interpolation. Yu-Sung Chang says here that "it is not hard to implement it ...
4
votes
1answer
70 views

What's the difference between Interpolation[pts, Method -> Spline] and BSplineCurve?

Last month, I answered a question about spline interpolation,please see here Now I do the following operations ...
16
votes
1answer
250 views

How can I smooth a 3D surface generated by RegionBoundary?

I have a set of points that belong to the surface of an object. I would like to approximate a surface to which I can compute the distance. of other points. With the nice code of this post, I was able ...
-1
votes
1answer
105 views

Multidimensional Interpolation with 3 independent Variables with modfied data set

I have four column data with first 3 column denoting x,y,z and fourth column energy. x variable is actually angle. Now I want to interpolate over all three indepdent variable (x,y.z) with ...
19
votes
3answers
3k views

Data interpolation and ListContourPlot

I am fairly new to Mathematica and I have two quick questions on using it for a Hydrology and Hydrogeology class. One is about data interpolation and interpolating without any data defined in an area. ...
20
votes
6answers
3k views

Finding the intersection of a curve with an interpolation function

There are no issues trying to find the intersection points of two defined curves. ...
22
votes
4answers
720 views

How to reduce the InterpolatingFunction building overhead?

I want a linear interpolation from the following example list: ...
2
votes
3answers
66 views

InterpolationOrder 2 or more in ListLogLinearPlot

I'm using the function ListLogLinearPlot, but the plot is to square, i would like to have InterpolationOrder 2, but there is not ...
0
votes
1answer
54 views

Interpolating a function of many variables

I am trying to interpolate a function of 5 variables $$f[m,M,k,v,w]$$ by creating a 5D table of $n$ values in each dimension. ...
2
votes
2answers
135 views

Approximation of definite integral by parabolas

This question is related to Trapezoid approximation to definite integral. As promised, I am now asking about how to draw approximation of integrals by parabolas. I tried to modify MarcoB's code, and I ...
4
votes
0answers
59 views

Multidimensional arbitrary precision spline interpolation on the grid

This question is a generalization of the previous one for multiple dimensions. In the answer to that question an implementation for the clamped spline interpolation for 1D case and arbitrary degree of ...
0
votes
2answers
308 views

Extract X value from corresponding Y value from a List or Transpose [duplicate]

I have a list of X values and Y values separately, and also together with: data=Transpose[{X,Y}] This data is from a chromatogram, and I want to extract the ...
9
votes
2answers
91 views
12
votes
2answers
322 views

Interpolation on a regular square grid spanning a triangular domain

Context I am trying to identify contours of a function which is sampled on a cartesian grid within an irregular (triangular) region. Here is the data ...
2
votes
1answer
67 views

Calculate the partial vapor pressures of a variable at xB = 0.75 based on the interpolation functions of the data

I'm having troubles in solving an exercise for an assignment in my Chemistry course. Talking about interpolations, I've already have a graph but I need to calculate the partial vapor pressures of ...
9
votes
5answers
309 views

Function for a series of joined slopes

I need a function for a series of joined slopes and my solution feels a bit kludgy. Is there a better way? A list of pairs of transition points and slopes: ...
2
votes
0answers
74 views

Defining a region from combination of data and geometric region

I would like to define a region in (x,y) by combining the region RegionPlot[ ImplicitRegion[ Sqrt[x^2 + y^2] <= 0.99, {{x, 0.01, 0.99}, {y, 0.01, 0.99}}]] ...
5
votes
3answers
220 views

Derivative of contour in ContourPlot

Sorry to bring this question up again, since there are many similar questions on the site. I use to think this is a easy job to do, because for the worst case I can follow the answers on this site. ...
11
votes
3answers
477 views

Subtracting two plots from each other after shifting one

I have the following lists representing energy spectra that need to be subtracted from each other to produce a difference spectrum. ...
9
votes
2answers
368 views

Interpolating an Antiderivative

I'd like to be able to make InterpolatingFunctions for antiderivatives of functions that can't be integrated symbolically. However, the following code returns ...
0
votes
1answer
50 views

List manipulation performance or how to make independent list copy

I have a task to solve some system of equations with NSolve and print graph of it, depends on parameters. Something like this (maybe it is not a good example and does not always have a solution, but ...
3
votes
2answers
143 views

Interpolation impossible for ListPlot with Missing?

I have a list of data to plot. I would like to plot them with lines but delete some data before plotting and leave the lines disconnected where data is deleted. For example, ...
0
votes
2answers
228 views

Interpolating a ParametricFunction

Original domain of my independent variable t is 0 to 10 nanometers, but in Mathematica (as in most numerical software), it's good idea to solve differential ...
0
votes
0answers
38 views

Extract x-values from InterpolatingFunction object? [duplicate]

Ok, So I have a numerical solution to a differential equation, and I am trying to get the data points out from it. So far, I have only been able to get the y-values with the following code: ...
-1
votes
1answer
54 views

Interpolation curve [closed]

I have a complicated parametric curve which takes too long to integrate, therefore I want to sample points and interpolate to speed up calculations. The curve is: ...
3
votes
3answers
294 views

Finding intersections of two parametric curves

I am dealing with the root finding of two parametric data curves (data below). I have already checked Parametric Interpolation of 2D data, which I found useful for plotting, though it is not adequate ...
15
votes
3answers
968 views

Parametric Interpolation of 2D data

I want to create an interpolation through the following 2dim data points: ...
9
votes
2answers
175 views

Build an InterpolatingFunction with ElementMeshInterpolation

Suppose you have a function f[t_, x_, y_] := t (1 - x^2 - y^2) defined for {x,y} in ...
1
vote
0answers
145 views

How to write my own interpolation method [duplicate]

I was comparing results of spline interpolation in Mathematica and C++/gsl-library Results of interpolation are different if I use ...
-2
votes
1answer
96 views

Interpolate/extrapolate a gate charge curve from two different curves

Gate charge measured data. I have gate-charge measurement plots and Excel data for two operating points for a power MOSFET. Vds = 60 V, Id = 50 A Vds = 600 V, Id = 8 mA Can I generate a plot with ...
5
votes
1answer
123 views

Intersection of a ListPlot3D surface with a plane

I'm trying to use Mathematica to analyze some physics data from an experiment, more precisely, I have to fit a 2D data series with a one dimension function. At the moment I'm able to load and plot ...
1
vote
0answers
41 views

Using Quantity[] units causes errors in my calculation

I have an interpolation function in which I wish to use actual units. If I perform the calculation normally, it works fine and returns a proper FittedModel. To illustrate my problem, consider the ...
0
votes
0answers
78 views

Polynomial interpolation using Neville's Algorithm

Is there an interpolating function in Mathematica which uses Neville's algorithm? I have written a C++ program to do interpolation using Neville's algorithm and I am getting a small difference ...
1
vote
2answers
59 views

How to generate commands which are very similar?

I have several data sets that I wish to interpolate and integrate like this: ...
8
votes
2answers
119 views

Changing the `ExtrapolationHandler` Function in Any Interpolation

This is a related question to What's inside InterpolatingFunction[{{1., 4.}}, <>]? and Suppress extrapolation of interpolating function in a ContourPlot. When interpolating a set of ...
5
votes
1answer
134 views

Finding minimum fly-by radius between Mars and spacecraft from interpolating function

I've written an interplanetary trajectory solver/plotter that plots the path taken by a spacecraft on an Earth-Mars mission, but have run into a little trouble when the spacecraft actually reaches ...