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Symbolic solve one equations - submatrix function?

philliard-disab
1-Newbie

Symbolic solve one equations - submatrix function?

I have a single equation that I am trying to get Mathcad 2001 to try to evaluate and simplify symbolically and it when the equation gets too complex, I get the message "This array has more elements than can be displayed at one time. Try using the submatrix function."

The problem is, there are no matrices in what I am trying to solve. One equation in a single unknown... How am I supposed to use the submatrix function?

Please see the attached Mathcad sheet for an example. It is a simpler version of the equation I am trying to solve (which works fine) and a more complex version that gives the error. Does this mean that Mathcad cannot solve this equation... I know that there is an answer, it is just algebraically intense.
8 REPLIES 8

Make a GIF of the animal. Versions previous to 2001 can not read your file. Pen in the...

Attached is a GIF of my problem...

On 7/5/01 12:02:00 AM, jmG wrote:
>Make a GIF of the animal.
>Versions previous to 2001 can
>not read your file. Pen in
>the...


Mathcad uses the Symbol Math from Maple - MKM (MathSoft Kernel Maple) � 1994 Waterloo Maple Software. And we can use some not documented in Mathcad functions from Maple. See for example a fig. 86 from my book "Tips for Mathcad Users" (find of integer (*i*solve) roots):

But some Maple functions works in Mathcad not correct or does not works or returns not correct error message:
">

We speak in Russia: "Maple's ears protrudes from Mathcad". So frequently it happens, when mix two software.
Valery Ochkov<<br> http://twt.mpei.ac.ru/ochkov

And then what?

Tom Gutman

And then what? What? I'm not sure what you're driving at.

In version 11.1 everything in your sheet works fine. That includes the original statement that didn't give a symbolic solution in version 2001.

Richard

>>In version 11.1 everything in your sheet works fine<<

As in 2001i. Except that in 2001i the original expansion is too large to show. If it shows in 11.1, I would think that the loosened the standard for display a bit.

So I was able to work out a way to reduce the expression to something that is displayable. Then what? What does one do with that display?

After my experience with the laser data fitting, I am becoming a big fan of working with expressions without looking at them. The symbolic solution was found, even back in the original sheet. The result can be used for further calculation, both numeric and symbolic. Why a concern with whether it can be looked at or not?

Tom Gutman

On 10/8/2003 3:11:40 PM, Tom_Gutman wrote:
>>>In version 11.1 everything in your sheet works fine<<
>
>As in 2001i. Except that in
>2001i the original expansion
>is too large to show. If it
>shows in 11.1, I would think
>that the loosened the standard
>for display a bit.
>
>So I was able to work out a
>way to reduce the expression
>to something that is
>displayable. Then what? What
>does one do with that display?
>
>After my experience with the
>laser data fitting, I am
>becoming a big fan of working
>with expressions without
>looking at them. The symbolic
>solution was found, even back
>in the original sheet.

Ah. I see. The subtlety of that point is rather missing when it is viewed in version 11. As you surmise, the restrictions have been relaxed.

> The
>result can be used for further
>calculation, both numeric and
>symbolic. Why a concern with
>whether it can be looked at or
>not?

Well, in principle one might learn something about the physics of the problem, even with very complex expressions. That is only "in principle" though!

Richard

>>That is only "in principle" though<<

Yes. And I think that principle is being stretched rather thin when you get to equations that are so large that Mathcad doesn't want to show them. Even with many that Mathcad is willing to show.

But a bit of preliminary simplification works wonders. Why is everything so much simpler the second time around?

Tom Gutman
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