wu :: forums
« wu :: forums - Find the eigenvectors on the TI-89 »

Welcome, Guest. Please Login or Register.
Nov 28th, 2024, 1:43pm

RIDDLES SITE WRITE MATH! Home Home Help Help Search Search Members Members Login Login Register Register
   wu :: forums
   riddles
   cs
(Moderators: Eigenray, william wu, ThudnBlunder, SMQ, Icarus, Grimbal, towr)
   Find the eigenvectors on the TI-89
« Previous topic | Next topic »
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: Find the eigenvectors on the TI-89  (Read 5263 times)
malchar
Junior Member
**






    malchar2
Email

Gender: male
Posts: 54
Find the eigenvectors on the TI-89  
« on: Apr 9th, 2010, 7:59pm »
Quote Quote Modify Modify

This is probably real easy for most of the people in this forum. Anyway, I'm just finishing my first year of computer science, and I've taken to making my own programs on the TI-89 (graphing calculator). I'm still working on my current program, but maybe someone else would be interested since it's a pretty easy introduction to CS.
 
Create a program that takes a matrix and displays the eigenvalues and eigenvectors.
 
The problem I'm currently mulling over is how to properly calculate and output the case where certain eigenvalues are duplicates, in which the associated eigenvector should be a multidimensional span.
IP Logged
Obob
Senior Riddler
****





   


Gender: male
Posts: 489
Re: Find the eigenvectors on the TI-89  
« Reply #1 on: Apr 9th, 2010, 8:26pm »
Quote Quote Modify Modify

Last I checked, a TI-89 has built in eigenvector and eigenvalue commands...
 
If you want to code it from more elementary functions, you'll need to really come to grips with the linear algebra.  In particular, if you have repeated eigenvalues, it doesn't automatically mean you have a multidimensional eigenspace:  for instance, the matrix
 
1 1
0 1
 
has the eigenvalue 1 with multiplicity 2, but its only eigenvector is the vector (1,0).
 
Unless the calculations are being performed exactly, numerical stability is a huge issue in trying to find eigenvectors and eigenvalues by computer.  The algorithm you would use to find eigenvectors and eigenvalues by hand is poorly suited to computer implementation, especially if you matrix might be defective (i.e. is non-diagonalizable).
« Last Edit: Apr 9th, 2010, 9:02pm by Obob » IP Logged
malchar
Junior Member
**






    malchar2
Email

Gender: male
Posts: 54
Re: Find the eigenvectors on the TI-89  
« Reply #2 on: Apr 10th, 2010, 12:37pm »
Quote Quote Modify Modify

Yes, they do already have those functions. Anyway, I didn't know quite how hard it would be to make my own programs. I'll continue to work with it a bit.
IP Logged
Pages: 1  Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Powered by YaBB 1 Gold - SP 1.4!
Forum software copyright © 2000-2004 Yet another Bulletin Board