Difference between revisions of "ElemSymPoly"

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|desc=Computes the elementary symmetric polynomial of a given set of numbers.
 
|desc=Computes the elementary symmetric polynomial of a given set of numbers.
 
|cat=[[List of functions#Miscellaneous|Miscellaneous]]
 
|cat=[[List of functions#Miscellaneous|Miscellaneous]]
|upd=August 22, 2024
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|upd=August 23, 2024
 
|v=0.90}}
 
|v=0.90}}
 
<tt>'''ElemSymPoly'''</tt> is a [[List of functions|function]] that computes the ''k''<sup>th</sup> [https://en.wikipedia.org/wiki/Elementary_symmetric_polynomial elementary symmetric polynomial] of a given set of numbers.
 
<tt>'''ElemSymPoly'''</tt> is a [[List of functions|function]] that computes the ''k''<sup>th</sup> [https://en.wikipedia.org/wiki/Elementary_symmetric_polynomial elementary symmetric polynomial] of a given set of numbers.
  
 
==Syntax==
 
==Syntax==
* <tt>res = ElemSymPoly(x, k)</tt>
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* <tt>RES = ElemSymPoly(X, K)</tt>
  
 
==Argument descriptions==
 
==Argument descriptions==
* <tt>x</tt>: A vector of length <tt>n</tt>.
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* <tt>X</tt>: A vector of length <tt>n</tt>.
* <tt>k</tt>: An integer denoting the degree of the terms in the elementary symmetric polynomial. Must be between <tt>0</tt> and <tt>n</tt>, inclusive.
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* <tt>K</tt>: An integer denoting the degree of the terms in the elementary symmetric polynomial. Must be between <tt>0</tt> and <tt>n</tt>, inclusive.
  
 
==Example==
 
==Example==

Latest revision as of 14:07, 26 August 2024

ElemSymPoly
Computes the elementary symmetric polynomial of a given set of numbers.

Other toolboxes required none
Function category Miscellaneous

ElemSymPoly is a function that computes the kth elementary symmetric polynomial of a given set of numbers.

Syntax

  • RES = ElemSymPoly(X, K)

Argument descriptions

  • X: A vector of length n.
  • K: An integer denoting the degree of the terms in the elementary symmetric polynomial. Must be between 0 and n, inclusive.

Example

This function computes the sum of products of k distinct elements of a vector x. For example, the 3rd elementary symmetric polynomial of the vector [1, 2, 3, 4] is computed by summing the distinct products of 3 elements, these products being 1 x 2 x 3, 1 x 2 x 4, 1 x 3 x 4, and 2 x 3 x 4.

>> ElemSymPoly([1, 2, 3, 4], 3)

ans =

    50

Notes

The 0th elementary symmetric polynomial is defined as S0(x) = 1.

Source code

Click here to view this function's source code on github.