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solve,L Not working

RWickrama
10-Marble

solve,L Not working

I am exploring solving equations.

Took a utube video.

My workng file attached here to.

2024-12-28 23_56_32-Mathcad Prime - Solve Blocks & Symbolics Webinar - YouTube and 1 more page - Per.png

2024-12-28 23_51_02-PTC Mathcad Prime 10.0.1.0 - D__Vault WS_Vault Projects_TRAINING_02 MATHCAD_01-0.png

I would like to get around this issue,

Pl. help.

 

ACCEPTED SOLUTION

Accepted Solutions

Do it as indicated. 

One equation (shown one) sets a result to a comparison resulting in Pseal either one or zero. so the equation being solved is -(G*(lambda-1/lamda^2)*so equal to 1 or zero.  Then sets Pseal to the answer.

The first simply needs a unit added for the equality comparison to make sense.

Capture.JPG

View solution in original post

6 REPLIES 6

Do it as indicated. 

One equation (shown one) sets a result to a comparison resulting in Pseal either one or zero. so the equation being solved is -(G*(lambda-1/lamda^2)*so equal to 1 or zero.  Then sets Pseal to the answer.

The first simply needs a unit added for the equality comparison to make sense.

Capture.JPG

@terryhendicott 

Are you using the current Prime 10.0.1.0 ?

When I open your sheet and let it recalculate i get an error (variable P.seal not defined)

Reason seems to be the inline evaluation after the definition of P.seal.

Werner_E_0-1735483451448.png

When I delete the inline assignment, I see this:

Werner_E_1-1735483540068.png

 

Only if I define P.seal using the the unit psi right away it works as desired (and it does not matter if the unit psi is added to the zero or not)

 

Werner_E_2-1735483785920.png

The symbolics used to use the latest expression in a series of evaluations and so it should use the value in psi when we use the inline evaluation.

I don't know why it throws an error when using the inline eval now and it looks to me as a new bug.

 

So if you don't use the latest release of Prime 10 it may be a bug introduced in the latest 10.0.1.0

EDIT: It may have nothing to do with the latest release but seems to be a problem with a combination of language setting and unit system setting.
See my answer below.

 

 

 

Werner_E
25-Diamond I
(To:Werner_E)

Hah!!

The aforementioned results were obtained when using Prime 10 in its native language setting which is German in my case.

When I start Prime using the command line parameter "/culture:en-US" to run in English, I get the desired result when I let the sheet of @RWickrama  recalculate without making any changes..

Werner_E_3-1735484386832.png

@RWickrama 

Which language do you use Prime in?

 

Further  observations using Prime in German:

When I let the original sheet recalculate, I get again the undefined variable error:

Werner_E_4-1735484728326.png

 

When I switch from unit system USCS to SI, I get this

Werner_E_5-1735484816493.png

 

Of course the symbolics does not know anything about units and can't see that Pa and psi are units of the same dimension,

So I used inline evaluation at the definition of G as well to use Pa instead of psi, and , voila!

Werner_E_6-1735484957509.png

 

So its clearly a bug. The problem is a combination of language setting and unit system setting.

Somebody may care to report it to PTC R&D.

 

Thank you for your kind help that led me to gain more knowledge in Mathcad Prime.

I use English language (only).

Thank you, sir.

Not sure why I forgot to match units. I may not not forget again.

LucMeekes
23-Emerald III
(To:RWickrama)

You could first solve for the general solution, then fill in the data. Like this:

LucMeekes_0-1735469438998.png

(Gives a huge result vector, potentially too large to display.

LucMeekes_1-1735469493127.png

But you now have a function lambda of three parameters that you should be able tom use.)

Then  define your data:

LucMeekes_2-1735469555130.png

And calculate the result:

LucMeekes_3-1735469586590.png

In case you are only interested in the real result (as opposed to the complex ones):

LucMeekes_4-1735469783880.png

But if you specifically want a complex result:

LucMeekes_5-1735469841560.png

 

Success!
Luc

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