Symbolic lsolve

[AlvaroDíaz]

Hi.

¿There are a way to catch the values for this kind of lsolve?

Thanks in advance.

Alvaro.

[Fred_Kohlhepp · Accepted solution]

[AlvaroDíaz]

Hi Fred.

Thanks for your reply. I don't have any idea about why your proceducre doesn't converge but mine yes.

Best regards.

Alvaro.

[RichardJ]

It doesn't converge to a solution for me either.

I don't see any easy way to split the two symbolic solutions out. The only approach I can think of is to use the automation interface to read the XML of the region and then create the vectors in two other regions.

[AlvaroDíaz]

Hi Richard. I don't think in that. Actually it is a good idea, but Prime gives a string as answer.

Best regards.

Alvaro.

[VladimirN]

Richard Jackson wrote:

It doesn't converge to a solution for me either...

In MC15 M045? I got the same result in this service release as Alvaro.

[AlvaroDíaz]

Hi Fred.

Thanks again, but now for the picture of Prime result. Instead of correct the answer format, just inform that it is invalid. Nice practice.

Best regards.

Alvaro.

[ValeryOchkov]

But in Prime with new Solver we have not two but one answer - one from infinity:

[AlvaroDíaz]

Hi Valery.

Thanks for the method of guessing with one vector to find another; both seems (or are evidently) linearly independent. I'm going to test it.

What I'm actually looking for is for the nullspace or kernel of a matrix, as step for write the Jordan form of a matrix.

Best regards.

Alvaro

[ValeryOchkov]

Three pictures from the book Физико-математические этюды с Mathcad и Интернет

[AlvaroDíaz]

I don't see that book, it's excelent. Thanks Valery.

Alvaro.

[ValeryOchkov]

AlvaroDíaz написал(а):

I don't see that book, it's excelent. Thanks Valery.

Alvaro.

You can download the book and translate it into English or Spain

http://twt.mpei.ac.ru/ochkov/T-2016/PhysMathStudies.pdf

[AlvaroDíaz]

Hi Valery. Thanks. Let's me try.

Best regards.

Alvaro.

[ValeryOchkov]

Thanks, amigo Alvaro!

Some parts was translated:

http://twt.mpei.ac.ru/ochkov/MathLit.pdf

http://twt.mpei.ac.ru/ochkov/SPB-Moscow-Train.pdf

http://twt.mpei.ac.ru/ochkov/teaching_of_math.pdf

The parts of book of Valery Ochkov

etc

[Werner_E]

I see no easy way to get hold on the two vectors of the symbolic result, but I get the very same result as shown in the picture by Alvaro when I load his sheet in Mathcad M030.

Not sure which releases are used by Alvaro, Fred and Richard.

In Prime 3.0 I experience the same as Fred has shown.

[RichardJ]

I use M045. Why are you still using M030?

[AlvaroDíaz]

HI Richard. Mathcad M040. Is the edition that use almost all the students.

Best regards

Alvaro.

[VladimirN]

AlvaroDíaz wrote:

... use almost all the students...

Alvaro,

Werner Exinger - is student ? Or "eternal student" ?

[AlvaroDíaz]

Hi Vladimir.

Eternal.

Just like, I guess, all of us.

Actually I have some bad memories from my student times about calculating Jordan Forms. Even with the HP 41 CV help.

Seems that those regards are looking for me.

Best regards.

Alvaro.

[Fred_Kohlhepp]

I'm way over my head, but

https://ocw.mit.edu/courses/mathematics/18-06sc-linear-algebra-fall-2011/positive-definite-matrices-and-applications/sim…

[AlvaroDíaz]

Hi Fred.

Yes, it is. But for this matrix it's 'easy', problem is for some general case, where eigenvectors don't give all the results.

Best regards.

Alvaro.

[Werner_E]

Richard Jackson wrote:

I use M045. Why are you still using M030?

Laziness 🙂

Still working with Win XP.

As Alvaro is using M040, behavior seems to have changed from M040 to M045. Bug or feature?

[AlvaroDíaz]

Hi Werner.

Industry is still using win XP, and whith some luck, office 2010. If not, 2007, or not office at all. They say that XP is from eXPeriment, not from eXPerience.

Best regards.

Alvaro.

[Werner_E]

Thanks, so I feel much better now

Regards

Werner

[RichardJ]

I stuck with XP for a long time. I eventually switched to Win 7 with XP mode installed for the few pieces of software (most notably MC11) that would only run under XP. I finally gave up and switched to Win 10 a few days before the free upgrade offer ran out (it turns out you can actually still get the free upgrade though). So now I no longer have easy access to MC11 . I have to fire up my old XP machine, which is so old I have to reset the date and time in the BIOS every time I boot it

[RichardJ]

Bug or feature?

Well, as Andy notes below, there are only two independent equations. So I could argue that it's a feature. That would require me to believe there was actually intent on the part of a PTC programmer to change the behavior though. Hmmm....

[Werner_E]

Richard Jackson wrote:

That would require me to believe there was actually intent on the part of a PTC programmer to change the behavior though. Hmmm....

And then Fred states that he is also using MC 15 M030 and he gets the error, too. So it looks like it hats nothing to do with the service release but with something else - no clue what it could be, though.

[AlvaroDíaz]

Feature, fueature!

It for eval the nullspace of a matrix.

Best regards.

Alvaro.

[Fred_Kohlhepp]

I'm using 15 030  (lazy IT group.)

Prime 3.9 F000

[VladimirN]

Fred Kohlhepp wrote:

Prime 3.9 F000

Secret service release?