Help for a "Surface and Flux integrals" program

[Arno K]

Another topic to be documented.
Arno

[Arno K]

(11-06-2017 06:49 PM)salvomic Wrote:  

(11-06-2017 06:37 PM)Arno K Wrote:  No no, now it works, but I am not that contented with implementing of local variables and then purging them to avoid their occurance in memory-manager.
Arno

I know, you are right, that's only a workaround, but the occurrence in memory manager leaves there variables that after some time could interfere with other commands or programs...
We need a real solution :-)

Salvo

I added to the posted program the two lines with purge(u) and purge(v) and made u and v local until the problem is solved.

[salvomic]

(11-06-2017 08:57 PM)Arno K Wrote:  I added to the posted program the two lines with purge(u) and purge(v) and made u and v local until the problem is solved.

you have done well. When there will be a better solution we'll be able to avoid local u and v and also purge()...

I have done the same in my program for Linear and curvilinear integrals (in Library) for the same purpose.

[parisse]

There is no better solution! Declaring symbolic variables as local variables and purge them after (or assume(.,DOM_SYMBOLIC)) is the recommanded way to use symbolic variables in a CAS function.

[salvomic]

(11-07-2017 07:13 AM)parisse Wrote:  There is no better solution! Declaring symbolic variables as local variables and purge them after (or assume(.,DOM_SYMBOLIC)) is the recommanded way to use symbolic variables in a CAS function.

well, thank you. I'm using this method and it's ok.

[Arno K]

Does not work anymore.
Arno

[salvomic]

(12-02-2017 05:02 PM)Arno K Wrote:  Does not work anymore.
Arno

sfint()?
and why? what is changed?

I'm trying the example you wrote:

Code:


The surface of a paraboloid is then calculated:
sfint(1,[u*cos(v),u*sin(v),u^2],[0,1],[0,2*π]) which yields 1/6*(√5*5*π-π)

and I get still 1/6*(√5*5*π-π)...

Salvo

[Arno K]

It puts out shit on VC, works on HW, I will try a reset of VC and reinstall everything, I simply wanted to try debug with cas.
Arno
I cleared memory and reinstalled a backup, then it worked again, so upgrading still needs a memory wipe, at least from time to time.

[salvomic]

understood. I tried on HW and it worked...
Maybe time to time a refresh of memory is needed, yes.