Posynomial

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A posynomial is a function of the form

f(x_1, x_2, \dots, x_n) = \sum_{k=1}^K c_k x_1^{a_{1k}} \cdots x_n^{a_{nk}}

where all the coordinates xi and coefficients ck are positive real numbers, and the exponents aik are real numbers. Posynomials are closed under addition, multiplication, and nonnegative scaling.

For example,

f(x_1, x_2, x_3) = 2.7 x_1^2x_2^{-1/3}x_3^{0.7} + 2x_1^{-4}x_3^{2/5}

is a posynomial.

Posynomials are not the same as polynomials in several variables. A polynomial's coefficients need not be positive, and, on the other hand, the exponents of a posynomial can be real numbers, while for polynomials they must be non-negative integers.

[edit] References

  • Harvir Singh Kasana; Krishna Dev Kumar (2004). Introductory operations research: theory and applications. Springer. ISBN 3540401385. 

[edit] External links

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