How to enforcing simbolic evaluation?

#1 Pubblicato: 20/02/2021 03:17:40

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Even if the variable have been defined.

E.g. how to get x=(a+b）（a-b）even if a=1, b=2
File non trovato.File non trovato.

#2 Pubblicato: 20/02/2021 09:39:43

Jean Giraud

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#3 Pubblicato: 20/02/2021 10:20:42

netsonicyxf

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Thanks, but I want to know how to get U=(a+b )*(a-b ), even if a=1, b=2 is on the top

#4 Pubblicato: 20/02/2021 12:01:23

Jean Giraud

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Wrote
Thanks, but I want to know how to get U=(a b )*(a-b ), even if a=1, b=2 is on the top

I simply don't understand your request.
Read Martin handbook, to learn using Smath.

#5 Pubblicato: 20/02/2021 13:02:11

Martin_B

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I think the only way is to delete the defintions by using Clear(a;b)= .

#6 Pubblicato: 20/02/2021 13:15:24

Jean Giraud

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Wrote
I think the only way is to delete the definitions by using Clear(a;= .

No need, algo is self clearing.

#7 Pubblicato: 20/02/2021 17:18:06

Jean Giraud

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No need, algo is self clearing.

#8 Pubblicato: 21/02/2021 01:25:56

Alvaro

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Wrote
Even if the variable have been defined.

E.g. how to get x=(a+b）（a-b）even if a=1, b=2

Hi. As MarB says, only with Clear(a , b ) in SMath. However, it is true that in Mathcad you can hide the numeric values for a symbolic evaluation:

Best regards.
Alvaro.

#9 Pubblicato: 21/02/2021 09:24:07

netsonicyxf

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Wrote
I think the only way is to delete the defintions by using Clear(a;b)= .

Wrote

Hi. As MarB says, only with Clear(a , b ) in SMath. However, it is true that in Mathcad you can hide the numeric values for a symbolic evaluation:

really wish Smath can perform like MathCAD

#10 Pubblicato: 21/02/2021 11:00:13

Jean Giraud

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Wrote
really wish Smath can perform like MathCAD

#11 Pubblicato: 21/02/2021 11:10:37

netsonicyxf

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Thanks Jean.

BTW, MathCAD doesn't need to do clearance.

#12 Pubblicato: 21/02/2021 12:00:32

Jean Giraud

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BTW, MathCAD doesn't need to do clearance.

True for that little example. More advanced stuff needs be cleared as well.
The symbolic arrow was demanded but not implemented.

#13 Pubblicato: 21/02/2021 13:27:04

Davide Carpi

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The only way is to define the variables after the expression, then you can show the expression using Clear. The other way doesn't works because when values are set before the expression, the values are stored in memory, not the variable names.

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#14 Pubblicato: 21/02/2021 13:28:15

Alvaro

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Wrote
Thanks Jean.

BTW, MathCAD doesn't need to do clearance.

Hi. It needs. That is the mean for a:=a and b:=b, which clear a and b only for symbolics, but not for numerics. If you want to show the symbilic value stored in x cleaning a and b after you define x, you can use line() in the definitions:

Also notice that you need to eval Clear(a, b ) = 1, if not SMath not recognize that as an instruction.

Best regards.
Alvaro.

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Davide Carpi 22/02/2021 05:37:00

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