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Ansatz

 

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Ansatz


 
 

In physics and mathematics, an ansatz is an educated guess that is verified later by its results. An ansatz is the establishment of the starting equation(s) describing a mathematical or physical problem. It can take into consideration boundary conditions. After an ansatz has been established, the equations are solved for the general function of interest. Typically, a word problemWord problem (mathematics education)

In mathematics education, a word problem is a mathematical question written without relying heavily on mathematical notation...
 starts by writing down the ansatz with subsequent refinement leading to the solution of the problem.

For example, given a setSet

In mathematics, a set can be thought of as any collection of distinct things considered as a whole....
 of experimental data that looks to be clusterCluster

A cluster is a small group or bunch of something....
ed about a line, a linear ansatz could be made to find the parameterParameter

In mathematics, statistics, and the mathematical sciences, parameters are quantities that define certain characteristics of...
s of the line by a least squaresLeast squares

Least squares is a mathematical optimization technique which, when given a series of measured data, attempts to find a funct...
 curve fit. Variational approximationApproximation

An approximation is an inexact representation of something that is still close enough to be useful....
 methods use ansätze and then fit the parameters.

Another example could be the mass, energy, and entropy balance equations that, considered simultaneous for purposes of the elementary operations of linear algebra, are the ansatz to most basic problems of thermodynamics.

Another example of ansatz is to suppose the solutions of a homogeneous linear differential equationDifferential equation

In mathematics, a differential equation is an equation in which the derivatives of a function appear as variables....
 and difference equation to have, respectively, exponential and power form. More generally one can guess a particular solution of a system of equations and test such an ansatz by direct substitution of the solution in the system of equations.

See also

  • ErsatzErsatz

    Ersatz is a German word literally meaning substitute or replacement....
  • GuesstimateGuesstimate

    Guesstimate is a portmanteau of the words guess and estimate....