[Scilab-users] Problem with partial fraction decomposition (dfss)

[tinnguyen]

Hi guys, 
I'm having trouble using scilab's function pfss to decompose a polynomial in
order to do inverse Z transform. Following is my code: 
--> z = poly(0,'z') 
--> hz = z^2 / (1 - 6*z + 11*z^2 - 6*z^3) 
--> pf = pfss(tf2ss(hz)) 
--> length(pf) 
The fourth command returns '1'. However, I believe it should be 3. I also
did the decomposition manually and got the result as: hz = 0.5/(1-z) + -1 /
(1-2*z) + 0.5/(1-3*z). 
Nevertheless, if I change the numerator of hz from z^2 to z or z^3, pfss
works correctly. I definitely have no idea!!!? :D
Please take a look and correct me if i'm wrong.
Thank you so much!




--
View this message in context: http://mailinglists.scilab.org/Problem-with-partial-fraction-decomposition-dfss-tp4031331.html
Sent from the Scilab users - Mailing Lists Archives mailing list archive at Nabble.com.