# Tagged Questions

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

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### How do I restrict the range of an interpolating function in NDSolve?

I have a numerical solution for a differential equation. I know that the gray dotted solution is unphysical. Is there a way I can tell mathematica to ignore the gray dotted solution (e.g. restrict the ...
340 views

### How can I speed up my compiled RBF interpolating function?

Overview I have a function that acts like the Interpolation on sparse $n$-dimensional data using a simple implementation of RBF interpolation method. I want my ...
62 views

### Can list interpolation be made listable? [closed]

I have 8 sets of 2D-data that I want to each interpolate with ListInterpolate, because it is a very efficient command. The complete data are therefore in a 3D table....
133 views

### Many NSolves to interpolating function

I have an expression of the form: expr = TerribleNumericalFunction[U[p]] == SimpleFunction[p] The Simple function is a ...
315 views

### Interpolation showing noise in “non-noisy” data set

Stuck trying to get the interpolating function to match the (what I thought was a) smooth point set, how best to deal with this? Many thanks. ...
283 views

### NMinimize Constraints on Interpolating Functions

I have the following piece of code and am trying to use NMinimize (the last line in the following chunk of code) to minimize ...
106 views

### Second derivative of SmoothKernelDistribution PDF?

Does anyone know why I can't seem to get a second derivative of this interpolating function f? In this example, h[x] is zero ...
228 views

### Smoothen the curve found by EdgeDetect

It seems that curves found by EdgeDetect always persist $C^{0}$ continuity only. Consider the following example: ...
461 views

### Why does LogLinearPlot sample its argument outside the specified domain?

Bug introduced in 6.0 and fixed in 9.0.0 I experience a weird bug in the function LogLinearPlot. If the input is an interpolation function, such as the one ...
162 views

### Kernel Crash while using “ValuesOnGrid” method of InterpolatingFunction

Bug introduced in 10.0.0 and fixed in 10.2.0 I was experiencing some kernel crash while using "ValuesOnGrid" method of an ...
225 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 ...
583 views

### Interpolation on a regular square grid spanning a triangular domain

Bug introduced in 10.0 and fixed in 10.1 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 <...
88 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. ...
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 ...
242 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" ...
18 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 = NDSolveValue[{y'[...
483 views

### How to fix broken InterpolatingFunction?

Fixed in Version 9 I have an InterpolatingFunction based on irregularly-gridded data, like this: ...
101 views

### How to find the best fit for given input data? [closed]

I have the following data: ...
592 views

### How to make BSplineFunction pass each data point and naturally smooth?

Old package, works good ...
416 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 ...
339 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 ...
146 views

### Multidimensional Interpolation with 3 independent Variables with modfied data set [duplicate]

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 ...
7k 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. ...
914 views

### How to reduce the InterpolatingFunction building overhead?

I want a linear interpolation from the following example list: ...
88 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 ...
393 views

### Failure in integrating from an interpolating function!

Consider a list like below: ...
178 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 ...
693 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 ...
139 views

### Finding self-intersections of a closed curve represented by an interpolation function

I've been trying to find particular simple closed curves on a plane. ...
73 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 ...
334 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: ...
313 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. ...
911 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. ...
533 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 ...
65 views

### How can I change the behaviour of InterpolationOrder -> 0? [duplicate]

Consider the following example: ...
70 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 ...
205 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, ...
242 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 ...
39 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: ...
79 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: ...
645 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 ...
1k views

### Parametric Interpolation of 2D data

I want to create an interpolation through the following 2dim data points: ...
317 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 ...
147 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 ...
113 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 ...
291 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 ...
56 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 ...
60 views

### How to generate commands which are very similar?

I have several data sets that I wish to interpolate and integrate like this: ...