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Sat, 29 Dec 2012 07:58:07 +0000
Rank of root
http://www.mathworks.com/matlabcentral/newsreader/view_thread/325461#894472
Triet
I know Matlab has "factor" to factor an equation, but is there any function or any way to do this in Matlab:<br>
Input: an equation ex: x^3 8*x^2 + 20*x 16<br>
Output: <br>
+the equation factored, ex: (x  4)*(x  2)^2<br>
+Solve the equation, ex: x1=4; x2=2<br>
+Most important: show the rank of each root (the power of each inner expression) , ex: root 1 = 4 has rank = 1; root 2 = 2 has rank = 2

Sat, 29 Dec 2012 17:56:11 +0000
Re: Rank of root
http://www.mathworks.com/matlabcentral/newsreader/view_thread/325461#894493
Roger Stafford
"Triet" wrote in message <kbm7qf$bn2$1@newscl01ah.mathworks.com>...<br>
> I know Matlab has "factor" to factor an equation, but is there any function or any way to do this in Matlab:<br>
> Input: an equation ex: x^3 8*x^2 + 20*x 16<br>
> Output: <br>
> +the equation factored, ex: (x  4)*(x  2)^2<br>
> +Solve the equation, ex: x1=4; x2=2<br>
> +Most important: show the rank of each root (the power of each inner expression) , ex: root 1 = 4 has rank = 1; root 2 = 2 has rank = 2<br>
        <br>
Besides the symbolic 'factor' there is the numeric 'roots' function from which you can obtain the above information by comparing the polynomial's roots. For a polynomial with real coefficients a pair of roots which are complex conjugates of one another will give you a quadratic factor. Note that roots which are equal may suffer slightly differing roundoff errors so your comparisons should have a tolerance for small differences.<br>
<br>
Roger Stafford

Sat, 29 Dec 2012 18:32:13 +0000
Re: Rank of root
http://www.mathworks.com/matlabcentral/newsreader/view_thread/325461#894494
Triet
"Roger Stafford" wrote in message <kbnarq$302$1@newscl01ah.mathworks.com>...<br>
> "Triet" wrote in message <kbm7qf$bn2$1@newscl01ah.mathworks.com>...<br>
> > I know Matlab has "factor" to factor an equation, but is there any function or any way to do this in Matlab:<br>
> > Input: an equation ex: x^3 8*x^2 + 20*x 16<br>
> > Output: <br>
> > +the equation factored, ex: (x  4)*(x  2)^2<br>
> > +Solve the equation, ex: x1=4; x2=2<br>
> > +Most important: show the rank of each root (the power of each inner expression) , ex: root 1 = 4 has rank = 1; root 2 = 2 has rank = 2<br>
>         <br>
> Besides the symbolic 'factor' there is the numeric 'roots' function from which you can obtain the above information by comparing the polynomial's roots. For a polynomial with real coefficients a pair of roots which are complex conjugates of one another will give you a quadratic factor. Note that roots which are equal may suffer slightly differing roundoff errors so your comparisons should have a tolerance for small differences.<br>
> <br>
> Roger Stafford<br>
<br>
<br>
Thank you. That helped me very much.