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Topic: Pseudo inverse: small deviations, large error
Replies: 1   Last Post: Jan 13, 2013 3:30 AM

 Messages: [ Previous | Next ]
 Peter Mairhofer Posts: 41 Registered: 8/18/10
Pseudo inverse: small deviations, large error
Posted: Jan 12, 2013 11:33 PM

Hi,

Can someone plain why I get such huge errors with only slight deviations?

>> Hf
Hf =

1.0e+003 *

1.6443 1.6516 1.6583
4.8373 4.8349 4.8334
4.6385 4.6418 4.6445
-9.6014 -9.6084 -9.6154

>> [yl1 , yl3 , yl1 - yl3 ]
ans =

1.0e+006 *

0.2966 0.2972 -0.0006
0.8705 0.8703 0.0002
0.8352 0.8355 -0.0003
-1.7288 -1.7295 0.0006

This is the correct result:

>> Hf \ yl1
ans =

100.0000
75.0000
5.0000

And now:

>> Hf \ yl3
ans =

56.0412
72.5578
51.4007

... unuseable results. I have much redundancy available, I can make the
rows of "Hf" very large but still get bad results.

Thanks,
Peter

Date Subject Author
1/12/13 Peter Mairhofer
1/13/13 Matt J