Evaluate elementary symmetric polynomials
6 views (last 30 days)
Show older comments
Claudio Bellani
on 13 Jul 2014
Answered: Roger Stafford
on 13 Jul 2014
Given n variables x_1...x_n and given an integer 1<=k<=n, I'd like to evaluate the k-th elementary symmetric polynomial, as defined -for instance- here:
My attempt was to store x=[x_1,...x_n], to define a vector j=[] of length k and then to execute
for j(1)=1:n
for j(2)=j(i):n
...
for j(n)=j(k-1):n
e=e + x(j(1))*...*x(j(k));
end...end
How to replace the dots?
0 Comments
Accepted Answer
Roger Stafford
on 13 Jul 2014
Let v = [x_1,x_2,x_3,...,x_n] be a vector of the values of x_i.
e = sum(prod(nchoosek(v,k),2));
0 Comments
More Answers (0)
See Also
Categories
Find more on Creating and Concatenating Matrices in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!