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Changing display format of symbolic solution

ptc-5058562
1-Visitor

Changing display format of symbolic solution

Hello,

Can anybody tell me if there is a possibility to change format of equation solved symbolically?

Mathcad+-+lab5.xmcd.png

I would like to get result such like a0/(1 * omega^2 - b0). How can i change coefficient standing by omega^2 to 1, for the rest to change adequately?

Second of all, thy does results differ, whether keywords are used one after another or used in batch?

9 REPLIES 9

Like so?

transform.PNG

Alan

Ok, but how about cases, when both nominator and denominator contains polinomial of n-th and m-th range? It was the simpliest example i had to solve, but there are more complex waiting

Karol Niemczyk wrote:

Ok, but how about cases, when both nominator and denominator contains polinomial of n-th and m-th range? It was the simpliest example i had to solve, but there are more complex waiting

I guess you would define H(s) in terms of unassigned variables, and make fn a function of those that remain after the second-line calculation, so you can substitute numerical values for them. If you supply a more complicated H(s) we can try it.

Alan

Honestly i've been thinkig of making universal function to calculate it for any input values. But it doesn't work. It casts "Patern match exeption"

Bez tytułu.png

Btw. next transmitances are as follow:

1. (s^2 + 3.431) / (s^2 + 0.5778s + 0.5408)

2. (s^2 + 8.106) / (s^2 + 0.1831s + 1.033)

3. (0.008093 * s^4 + 0.09338 * s^2 + 0.2251) / (s^5 + 1.164 * s^4 + 1.986 * s^3 + 1.373 * s^2 + 0.8393 * s + 0.2251)

Try separating numerator and denominator and dividing both by multipliers of leading term in denominator then recombining. Example below (arbitrary values used):

transform2.PNG

However, your last three examples don't need this extra complication, they work using the same approach as my previous post.

Alan

Werner_E
25-Diamond I
(To:ptc-5058562)

Think Alan has already answered your main question.

As to the strange behaviour of the symbolic evaluation - this is due to the fact, that Mathcads symbolics (which isn't state of the art, anyway) switches to a very nasty floating point mode as soon as only one single decimal point is present in the expression. Outcome in this mode (while probably mathematically correct to a certain level of numeric accuracy) can be really bizzare, sometimes. So whenever possible try to avoid decimals (not always easy, I know) in conjunction to symbolic evaluation.

formatsymbsol1.png

Thanks a lot. I'll keep this in mind. Nobody truly told me that before :S

Alan,

This is earily similar (the work around with the denominator) to the work around in the insulation problem we went through a few months back

AlanStevens
17-Peridot
(To:ELSID)

ELSID wrote:

Alan,

This is earily similar (the work around with the denominator) to the work around in the insulation problem we went through a few months back

Yes. Stay here long enough and you'll see the same things come up time and again. But that's a good thing because it means there are always new people getting involved.

Alan

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