Simple programing to recognize "negative solution"

[mar2805]

Hi folks!
Somethnig Im trying to do but simply cannot find the solution.
Few questions.

I have an quadriatic equation wich sometimes creates negative number under the root expression.
I would like Mathcad to write an expression when this happens.
I tried doing this with simple programing.
Basicly what I did is add to lines with two conditions:
1st) "NOT AVAILABLE" if .................... (this is where I get lost, how to tell him when you get negative number under the squareroot?)
2nd) "AVAILABLE" otherwise


Is it possible to hide the function (expression) for wich you are finding the solution.
Like in previous egsample X:= two mentioned programing lines
Wich would finaly give X = something
How to hide "X=" so that you only see the result?


When using programing lines is it possible to define two action for one conditions and one action for the second condition?
Egsample if I have equation x-3=0
II"AVAILABE" I
II I if x>0
II"X=5" I
I "Not available" othervise

So basicly if x gives soution >0 I would like Mathcad to report an "AVAILABE" comment and give the solution x=5

Any chance for something like this?
Thank you.

 

[mar2805]

Hi!
Heres the same solution (thanx to you) in another way.
But I dont understand how can MATHCAD calculate z value thats "under 5" if I didnt define the last programing line as "x1"?
Its seems that it went thru the last condition "greater then 5" if root(........)>5" saw that its not valid and anyway calculated the value.
On the other hand if I put 3rd programing statement as "x1" as soon my root equation is not vaild it returns error.
IRstuff whats your opinion?

 

[IRstuff]

It doesn't need to be on the last line, it just needs to have been assigned and not over-written, and it needs to still be running the program.

As in algebra, order of operations is important, with the additional wrinkle that you have the option of ending the program prematurely. So, you have to pay particular attention to what you've commanded in the logical flow of the program. This is what makes programs so difficult to debug and maintain, which is further compounded by the innate lack of debugging tools in Mathcad.

http://files.engineering.com/getfil...2f-41fe-9b01-92a6b66a0cba&file=Problem2e.xmcd

TTFN
faq731-376

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[rmix22]

Maybe the attached file can be of help.

 

[rmix22]

As you asked initially for some kind of message textbox without "x=" - here is a solution using scripted components. Mathcad will ask you when you open the sheet and you will have to enable objects by clicking "No".

 

[rmix22]

Isn't there a way to edit or delete a posting?
OK, here is a slightly modified/corrected version of the file.

 

[mar2805]

@IRstuff
Thank you very much!
Egsamples you posted where realy helpfull in understanding the importance order when programing with MATHCAD

@rmix22
How did you use these scriptable components?
Insert-> Component-> ???

 

[rmix22]

How did you use these scriptable components?

Basically yes. The specific here was copied from another sheet of mine and then the VB code edited to fit your needs.

 

[rmix22]

@mar2805: Sorry, I missed your ???'s

It's: Insert/Control/Text Box
then RightClick - Add InputVariable
then RightClick - Edit script
and off we go using VBScript commands
At last to clean up I chose to Hide Arguments (again RIghtClick)