Questions tagged [interpolation]

Questions on interpolation, the estimation of the value of a function from given input, based on the values of the function at known points. It is necessary because in science and engineering we often need to deal with discrete experimental data.

Interpolation is a useful mathematical and statistical tool used to estimate values between two points on a line or curve.

What Is Interpolation?

Interpolation is the process of deriving a simple function from a set of discrete data points so that the function passes through all the given data points (i.e. reproduces the data points exactly) and can be used to estimate data points in-between the given ones.

To help us remember what it means, we should think of the first part of the word, 'inter,' as meaning 'enter,' which reminds us to look 'inside' the data we originally had.

Applications: This tool, interpolation, is not only useful in statistics, but is also useful in science, business or any time there is a need to predict values that fall within two existing data points. It is also used to simplify complicated functions by sampling data points and interpolating them using a simpler function. In the mathematical field of numerical analysis, interpolation is a method of constructing new data points within the range of a discrete set of known data points. In engineering and science, one often has a number of data points, obtained by sampling or experimentation, which represent the values of a function for a limited number of values of the independent variable. It is often required to interpolate, i.e., estimate the value of that function for an intermediate value of the independent variable.

The details, techniques, and precise meaning of interpolation depend heavily on the sub-discipline of mathematics, therefore you are encouraged to use additional subject tags such as , , , or when appropriate.

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Linear interpolation optimization

I want to interpolate any function $f(x)$ using only linear interpolation. So far I have found that the following equations do the trick pretty well. $$m(a,b,x)=\frac {f(b)-f(a)}{b-a}(x-a)+f(a)$$ $$L(a,b,x)=(a-x)(x-b)$$ $$T(x)=\frac 12(1+\mathrm…
GuPe
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Is it posible to interpolate convex hull in 2d space

I have $n$ points (in this example $11$) and I need to interpolate them in such a way that I have a function $f(t) \rightarrow (R, R)$ where $t \in [0; 2\pi]$. It can be parametric curve, but I need to have a function.
jcubic
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How to determine a function from data $2$-dimensional graph

I assume it is possible. Let us say I have $3$ years worth of water amount of rain collected everyday. A $2$-dimensional graph has been created from the data and there is pattern every year. How do I come out with a function?
Ron Vince
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How does Newton Interpolation work?

How does the Newton Interpolation work? The definition can be found here: http://www.nptel.ac.in/courses/122104018/node109.html Not how it's defined since that's mathematically clear, but I'm trying to grasp the general intuition about how it was…
mavavilj
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Existence of an interpolator of a finite data

I am wondering if the following problem has an affirmative answer: Does any finite dataset can be interpolated by a continuous and smooth function. Formally, let $E\subset \mathbb{R}^{n}$ be a finite set of cardinality N and let…
user157623
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Knowing two Vectors, and the distance to a 3rd, how to get the 3rd

If I know the two Vectors $v_1$ and $v_2$, which describe points in a 2D space, and I also know that a vector $v_3$ is on the line segment between $v_1$ and $v_2$, how can I get the $x$ and $y$ coordinates of $v_3$ if the only thing I know about…
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What equation would be used to be draw a curve like this?

I have created a little visual based programming system and am not working on the visuals, if two nodes are connected and B.x
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Lagrange interpolating polynomial

How can one find $$ L[x_0,x_1,..,x_n;\frac{1}{x+a}]?$$ The original problem asks for $$ L[x_0,x_1,..,x_n;\frac{x^{n+1}}{x\pm 1}]$$ I know there is a formula for $[x_0,x_1,..,x_n,\frac{f(x)}{a-x}]$, but I suppose it does not help.
user42768
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Developing a function of two variables from given data

Cross listed with Mathematica SE: https://mathematica.stackexchange.com/questions/66086/developing-a-function-of-two-variables-from-given-data I have been stuck on the following problem. Consider a system where we have three variables: force $F$,…
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Finding an algorithm to mark a lens barrel

I have a zoom lens that only has a handful of focal lengths marked on the zoom ring. I want to make some intermediate marks, but I don't know the math required. I do have the approximate angles of the factory-marked focal lengths. The lens zooms…
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Decrementing a value to a target value to reach a limit

Say we know a "limit" value A and an "initial increment" B as well as a "target increment" C where C < B << A Unfortunately I lack the skill to express this mathematically as this comes from a programming task, but hope this makes sense: Say we…
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What is and how to calculate quartic interpolation?

I was reading the gist on the reward function used in OpenAI Five, but I didn't understand the way they calculate health's reward. This is what they state: Hero health is scored according to a quartic interpolation between 0 (dead) and 1 (full…
Tirafesi
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