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4-Participant
November 3, 2023
Question

Issue with lsolve

  • November 3, 2023
  • 2 replies
  • 914 views

Hello!

 

I have a system of equations with units.  when I use lsolve, I get different answers (all incorrect) depending on the units used.  however, the solve block works correctly.  This is Prime 7.  sheet attached.

 

Any ideas?  maybe a bug in lsolve?  

 

ATschida_0-1699028461563.png

correct result:

ATschida_1-1699028522692.png

 

2 replies

21-Topaz II
November 3, 2023

Hi,

There is nothing wrong with lsolve().

lsolve() is being given different values to work on in each case like this.

Capture.JPG

Cheers

Terry

25-Diamond I
November 3, 2023

Obviously your system does not have a unique solution but more than one

No wonder as the determinant of Mx is very close to zero

Werner_E_0-1699049856499.png

 

The "correct" solution found with the solve block

Werner_E_1-1699049934790.png

but the solution found with lsolve seems to be OK as well

Werner_E_2-1699049987064.png

 

and

 

Werner_E_3-1699050339101.png