Solved

inverse matrix

Posted on 1997-12-11
19
528 Views
Last Modified: 2010-05-18
how can I get the inverse of a N x N matrix I need this code ASAP please very quick
0
Comment
Question by:latino
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 10
  • 5
  • 2
  • +2
19 Comments
 

Author Comment

by:latino
ID: 1256601
I Need this answer as soon as posible !!!!!!!!
0
 
LVL 10

Expert Comment

by:rbr
ID: 1256602
It depends on the size an shape of your matrix. If you need different algorithmen look for the book Numerical Recipies in C.

Online source code for this book at
http://
0
 
LVL 10

Expert Comment

by:rbr
ID: 1256603
Sorry i forgot the WWW-adress:
http://cfatab.havard.edu/nr/nronline.html
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:latino
ID: 1256604
http:// what???? there is no any answer, If please you can help me with the code I'll greatly appreciate it!!!!!!!!!

Ok let's say it's a 10 x 10 matrix

ASAP PLEASE
0
 

Author Comment

by:latino
ID: 1256605
This didn't help cause all I need is the code in that URL there is nothing about what I need

What if is a 10 x 10 matrix and I wanna find the inverse

PLEASE ASAP
0
 

Author Comment

by:latino
ID: 1256606
Still wating if EXPERTS can strike I'm here
0
 

Author Comment

by:latino
ID: 1256607
Still wating if EXPERTS can strike I'm here
0
 

Author Comment

by:latino
ID: 1256608
Godness Experts I really need this code I'll greatly appreciate
your assistance!!!!!!!!!!!!!!!!
0
 
LVL 10

Expert Comment

by:RONSLOW
ID: 1256609
here is 4x4 ... I'm looking for more for you...

From: gmt@aviator.cis.ufl.edu (Gary McTaggart)
Newsgroups: comp.graphics.algorithms
Subject: Re: Request: Inverse of a 4x4 matrix algorithm
Date: 21 May 1994 20:44:04 GMT
Mike Matsel (matsel@cs.uoregon.edu) wrote:

Does anyone have C code, or at least some psuedo-code for the finding the inverse of a 4 x 4 matrix? Its for a ray tracer. Thanks!
In a lot of cases in graphics, you will be strictly dealing with affine transforms. (My cheesy non-definition of affine is that you are only dealing with translations, rotations, and scaling. . .no shearing or perspective projection.) If this is the case, then you can use the following to find the inverse:


--------------------------------------------------------------------------------


// (Note that a Matrix is:
//   typedef float Matrix[4][4];
//
// Generally speaking, a matrix doesn't need to be bigger than 4x3, but
// since this code is to work with GL and it uses 4x4 matrices. . .

// Find the inverse of a matrix that is made up of only scales, rotations,
// and translations.
void MatrixAffineInverse( Matrix m, Matrix result )
{
  float Tx, Ty, Tz;

  // The rotational part of the matrix is simply the transpose of the
  // original matrix.
  result[0][0] = m[0][0];
  result[1][0] = m[0][1];
  result[2][0] = m[0][2];

  result[0][1] = m[1][0];
  result[1][1] = m[1][1];
  result[2][1] = m[1][2];

  result[0][2] = m[2][0];
  result[1][2] = m[2][1];
  result[2][2] = m[2][2];
 
  // The right column vector of the matrix should always be [ 0 0 0 1 ]
  // In most cases. . . you don't need this column at all because it'll
  // never be used in the program, but since this code is used with GL
  // and it does consider this column, it is here.
  result[0][3] = result[1][3] = result[2][3] = 0;
  result[3][3] = 1;

  // The translation components of the original matrix.
  Tx = m[3][0];
  Ty = m[3][1];
  Tz = m[3][2];
 
  // Rresult = -(Tm * Rm) to get the translation part of the inverse
  result[3][0] = -( m[0][0] * Tx + m[0][1] * Ty + m[0][2] * Tz );
  result[3][1] = -( m[1][0] * Tx + m[1][1] * Ty + m[1][2] * Tz );
  result[3][2] = -( m[2][0] * Tx + m[2][1] * Ty + m[2][2] * Tz );
}

0
 
LVL 10

Expert Comment

by:RONSLOW
ID: 1256610
Here is another at http://irecall.com/vve/matrix.c


0
 

Author Comment

by:latino
ID: 1256611
I can still wait for this a little bit more
thanks Ronslow
0
 
LVL 2

Expert Comment

by:kellyjj
ID: 1256612
Sounds like a homework assignment?  I have to ask you... Do you know how to get the inverse of a matrix by hand??  If you can't do it by hand then you really won't be able to understand or even write a program to do it for you.  

If you do know how to get the inverse by hand the just write code to do what you would do.  I know that it won't be the best code, but it will be a good starting point.
0
 

Author Comment

by:latino
ID: 1256613
you are right kelly it's a homework but I know how to get it by hand but this code should be able to get the inverse of a matrix bigger than a 4 X 4 and that's where I fall dowm! but I'll keep trying and see what I come up with

Thanks anyway
0
 
LVL 10

Expert Comment

by:RONSLOW
ID: 1256614
0
 

Expert Comment

by:hbadr
ID: 1256615
do you still want the code ??
0
 

Author Comment

by:latino
ID: 1256616
I do habdr!!! thanks
0
 
LVL 10

Expert Comment

by:RONSLOW
ID: 1256617
Why the reject ???
0
 
LVL 10

Accepted Solution

by:
RONSLOW earned 100 total points
ID: 1256618
Why the reject ???  
0
 

Author Comment

by:latino
ID: 1256619
Thanks Ronslow
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Preface I don't like visual development tools that are supposed to write a program for me. Even if it is Xcode and I can use Interface Builder. Yes, it is a perfect tool and has helped me a lot, mainly, in the beginning, when my programs were small…
This is a short and sweet, but (hopefully) to the point article. There seems to be some fundamental misunderstanding about the function prototype for the "main" function in C and C++, more specifically what type this function should return. I see so…
The goal of this video is to provide viewers with basic examples to understand and use structures in the C programming language.
The goal of this video is to provide viewers with basic examples to understand and use conditional statements in the C programming language.

749 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question