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JE_50769593-Newcomer
3-Newcomer
November 17, 2023
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MATRIX CONFUSION (Beginner to matrices)

  • November 17, 2023
  • 2 replies
  • 2584 views

Hello all. I am not new to Mathcad but am new to matrices and evaluations. What i am trying to figure out is how to tell Mathcad Prime 9.0 to automatically select incrementing rows from a previous matrix for use in an formula. Please see the attached screenshot from a manual. I can define the E matrix without issue, but am lost after that. I have tried setting n = 0 and ORIGIN = 0, but that doesnt do what I need. 

 

 

Best answer by Werner_E

A bit easier

Werner_E_1-1700309983262.png

 

I am way out of my comfort zone, but as I understand it the  values in vector A.c should add up to H, which is not the case with the formulas given.

IMHO a sign in NCMA EQ 7-57 is wrong and it should rather be

Werner_E_1-1700316087762.png

In the picture posted by @JE_5076959  the "n"'s are wrong and should be "N"'s, as n is used as a variable index ( @terryhendicott  used "i" instead in his sheet).
This is correct given in the NCMA manual

https://ncma.org/wp-content/uploads/2022/05/NCMA-SRW-Manual-FINAL.pdf

but the sign in that manual still is wrong, I think.

Just noticed that the simplification I have given above is also in that manual as EQ 7-56 😉

 

EDIT: @JE_5076959 
IMO you should mark the answer of @terryhendicott  as the correct one, not mine - after all it was his answer which provided the worksheet which possibly had answered your question about the handling of the matrices.

 

2 replies

W
Werner_E25-Diamond I
25-Diamond I
November 17, 2023

Please attach your worksheet so we can see where you fail

T
21-Topaz II
terryhendicott21-Topaz II
21-Topaz II
November 18, 2023

Here is one way.  Equations don't look right?

 

W
Werner_E25-Diamond IAnswer
25-Diamond I
November 18, 2023

A bit easier

Werner_E_1-1700309983262.png

 

I am way out of my comfort zone, but as I understand it the  values in vector A.c should add up to H, which is not the case with the formulas given.

IMHO a sign in NCMA EQ 7-57 is wrong and it should rather be

Werner_E_1-1700316087762.png

In the picture posted by @JE_5076959  the "n"'s are wrong and should be "N"'s, as n is used as a variable index ( @terryhendicott  used "i" instead in his sheet).
This is correct given in the NCMA manual

https://ncma.org/wp-content/uploads/2022/05/NCMA-SRW-Manual-FINAL.pdf

but the sign in that manual still is wrong, I think.

Just noticed that the simplification I have given above is also in that manual as EQ 7-56 😉

 

EDIT: @JE_5076959 
IMO you should mark the answer of @terryhendicott  as the correct one, not mine - after all it was his answer which provided the worksheet which possibly had answered your question about the handling of the matrices.

 

    J
    JE_50769593-NewcomerAuthor
    3-Newcomer
    November 20, 2023

    Thank you and @terryhendicott for the help. I believe I was getting lost in the definition of n and adding i. 

     

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