A function trisection that finds the root of a polynomial

[whitejm]

I need to write a function trisection that finds the roots of a polynomial by breaking the interpolation interval {[a,b] into 3 on each iteration. There are four input parameters, a row matrix with the coefficients of the polynomial, a, b, and the desired error. There are two output parameters, root: the root of the equation and n, the number of iterations. Any help is appreciated.

 

[GregLocock]

Well you seem to have a pretty complete spec of the requirement there. I usually write down the steps I intend to take as comments and then put code in between the comments.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[IRstuff]

Sounds like homework

TTFN
faq731-376

 

[FeX32]

Homework for sure. The name of the method is a dead give away. (missing)

Why don't you start with the Bisection method. It's efficient, and only takes about 20 lines of code. ...


Fe (IronX32)

 

[hacksaw]

interesting, with trisection you are using an interpolating quadratic as opposed to a linear interpolation, that is solved easily enough, for a more detailed explanation you might try

http://www.sciencedirect.com/science/article/pii/S0096300307008946

few of us can afford to browes engineering tips from work these days, good luck

 

[FeX32]

Also good luck viewing that article if you or your institution don't have a subscription...


Fe (IronX32)

 

[hacksaw]

oh yeah, pay per view adult entertainment for sure, but that is what it takes unless you do the math yourself,

I guess the alternative is a truncated newton's or secant method