Polynomials

Curve fitting, roots, partial fraction expansions

Polynomials are equations of a single variable with nonnegative integer exponents. MATLAB^®represents polynomials with numeric vectors containing the polynomial coefficients ordered by descending power. For example,[1 -4 4]corresponds tox²- 4x+ 4. For more information, seeCreate and Evaluate Polynomials.

Functions

`poly`	Polynomial with specified roots or characteristic polynomial
`polyeig`	Polynomial eigenvalue problem
`polyfit`	Polynomial curve fitting
`residue`	Partial fraction expansion (partial fraction decomposition)
`roots`	Polynomial roots
`polyval`	Polynomial evaluation
`polyvalm`	Matrix polynomial evaluation
`conv`	卷积和多项式乘法
`deconv`	Deconvolution and polynomial division
`polyint`	Polynomial integration
`polyder`	Polynomial differentiation

Topics

Create and Evaluate Polynomials
This example shows how to represent a polynomial as a vector in MATLAB® and evaluate the polynomial at points of interest.
Roots of Polynomials
Calculate polynomial roots numerically, graphically, or symbolically.
Integrate and Differentiate Polynomials
This example shows how to use thepolyintandpolyderfunctions to analytically integrate or differentiate any polynomial represented by a vector of coefficients.
Polynomial Curve Fitting
This example shows how to fit a polynomial curve to a set of data points using thepolyfitfunction.
Programmatic Fitting
There are many functions in MATLAB that are useful for data fitting.

Featured Examples

Predicting the US Population

Extrapolating data using polynomials of even modest degree is risky and unreliable.

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