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Talk:Gauss-Jordan matrix inversion: Difference between revisions

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Talk:Gauss-Jordan matrix inversion (view source)

Revision as of 09:26, 3 November 2018

4,215 bytes added ,  5 years ago
→‎what's wrong (with REXX)?: I don't see what you're seeing.
 
(→‎what's wrong (with REXX)?: I don't see what you're seeing.)
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The first elimination sets a.2.2=0 and how could this become 1 furtheron?
Help! Thanks!! --Walter Pachl 08:52, 3 November 2018 (UTC)
 
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I don't see your failure, &nbsp; '''a.2.2''' &nbsp; becomes zero and stays a zero.
 
Also, where it says <big> "Main diagonal has all ones" </big> isn't true.
 
With:
a= 3 1 8 9 6 6 2 8 10 1 5 7 2 10 3 3 2 7 7 9 3 5 6 1 1
{{out}}
<pre>
show 1 The given matrix
3 1 8 9 6 1 0 0 0 0
6 2 8 10 1 0 1 0 0 0
5 7 2 10 3 0 0 1 0 0
3 2 7 7 9 0 0 0 1 0
3 5 6 1 1 0 0 0 0 1
 
show 2 1
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 16/5 -34/5 -3 -21/5 -1 0 3/5 0 0
0 1 -1 -2 3 -1 0 0 1 0
0 4 -2 -8 -5 -1 0 0 0 1
 
show 2 2
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
 
show 2 3
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
show 2 4
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
Lower part has all zeros
 
show 3
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
show 4 5
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
show 4 4
3 1 8 9 6 1 0 0 0 0
0 0 -4 -4 -11/2 -1 1/2 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
show 4 3
3 1 0 1 -5 -1 1 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
show 4 2
3 1 0 1 -5 -1 1 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 4 4 11/2 1 -1/2 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
Upper half has all zeros
 
show 5
1 1/3 0 1/3 -5/3 -1/3 1/3 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 1 1 11/8 1/4 -1/8 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
 
Main diagonal has all ones
 
show 6 The inverse matrix
-1/3 1/3 0 0 0
0 0 0 0 0
1/4 -1/8 0 0 0
0 0 0 0 0
0 0 0 0 0
 
The product of input and inverse matrix
1 1/3 0 1/3 -5/3
0 0 0 0 0
0 0 1 1 11/8
0 0 0 0 0
0 0 0 0 0
</pre>
I would add the statement &nbsp; (at least for now):
 
signal on noValue
 
as you have a piece of dead code (possibly a debugging leftover?):
 
ss=sigl
 
-- [[User:Gerard Schildberger|Gerard Schildberger]] ([[User talk:Gerard Schildberger|talk]]) 09:25, 3 November 2018 (UTC)
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