Hi. Can the Maxima plugin beheavior could be changed to agree with SMath (and Mathcad) diff operator, when the variable is defined?:

MaximaDiff.sm (6 КиБ) скачан 83 раз(а).



Thanks in advance for your answer.
Alvaro.

Wrote

Hi. Can the Maxima plugin beheavior could be changed to agree with SMath (and Mathcad) diff operator, when the variable is defined?:

Thanks in advance for your answer.
Alvaro.

This would require access to the unevaluated (non-preprocessed) verbatim expression from within the plugin. I don't know if that is currently possible. Same problem applies for definite integrals for numeric evaluation. I could take over numeric quadrature as well if I had access to the unevaluated expression.

Perhaps our other developers have a quick anwer?

Wrote

This would require access to the unevaluated (non-preprocessed) verbatim expression from within the plugin. I don't know if that is currently possible. Same problem applies for definite integrals for numeric evaluation. I could take over numeric quadrature as well if I had access to the unevaluated expression.

Perhaps our other developers have a quick anwer?

Hi Martin. Clean() seems to have this kind of access.

Best regards.
Alvaro.

Wrote

Hi Martin. Clean() seems to have this kind of access.
Best regards.
Alvaro.

Clear() is defined in the Special functions plugin, which is closed source and probably isn't restricted to the third party plugin API.
The Maxima plugin has already survived several API changes, sometimes Andrey made adjustments even to third party plugins immediately, sometimes major re-work is required and update delays result from that. Unfortunately, I probably will only get up and running again with Visual Studio in summer. There is quite a todo list for the maxima plugin.

Maxima has it's own mechanism for suppressing evaluation/simplification, the so called "noun" property (inactive expression). I filed support for this in the plugin as request SS-3478

Hi Martin. I see the request SS-3478. But I guess that this isn't related with the noun Maxima's property (x::uneval in maple, and Hold[] in Mathematica. Actually I ask some time ago something like this related with derivatives of cool prop package).

I guess that defining


where the difference with normal call is ref Store context, and then


you can handle the case where an argument is defined, catching the variable name, and trying to determine if it is defined or not.

Actually I paste both of them from Maxima plugin source code. (But the second is commented).

Best regards.

Wrote

Actually I ask some time ago something like this related with derivatives of cool prop package).

That's interesting, Alvaro.
My understanding is that the underlying equations are IAPWS, to be tracable.
As implemented in Smath just a cluster fuck. OK, I don't need, using WASP
from Katmar. Under the hood, those functions are monkey business. I say that
because I coded those animals from personal transmission from Bernhard S.
I coded in VB. ALL OK, coded nearly all in Mathcad OK.
About your point of getting the derivative in Smath: not possible.
Not possible unless CoolProp re-coded from A ...Z.
In Smath CoolProp, you just get the interpolated value.
Most probably, those properties are respective data sets, interpolated.
IAPWS are a soup of polynomials. Correctly implemented, you will have
them on plot and derivatives.
I believe this package is the one from Valery at the time of his
web Mathcad calculator.
If interested, can check if still on my MCD 11.
I have most of IAPWS in Smath otherwise approximated, hyper accurate !

Cheers Alvaro ... Jean

PS: WASP from Katmar is not freeware but you have unlimited sessions
of 3 minutes [originally it was 10 minutes].

Hi. There are some issue here:



maxima_laplace.sm (5 КиБ) скачан 80 раз(а).

Best regards.
Alvaro.

Wrote

Hi. There are some issue here:

The problem seems to be the pre-mature execution of at() on SMath side. You see that if you switch off the Custom Functions plugin, then the answer is correctly displayed. Thus it isn't a translation issue. It would be desirable to keep the unevaluated response at least if optimization is set to "none".

I need to see if the Maxima plugin can do anything about it or even is the culprit.

Thank you for pointing this out. Filed as SS-4597.

Hi Martin. Thanks. Here, exp instead e^ seems to avoid this issue.

Implementation of the Laplace method solving a system of odes with Maxima laplace and ilt transforms, and it's comparative with numerical solution.

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Best regards.
Alvaro.

Same as before, but with a system without a close form for the inverse laplace.

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Laplace_Maxima2.pdf (160 КиБ) скачан 79 раз(а).

Best regards.
Alvaro.

Wrote

Here, exp(x) instead e^ seems to avoid this issue.

As I mentioned this to Reg few days ago, then spot checked in Smath.
No difference was observed on the 15 D results. In Mathcad, yes e^
is less accurate than exp(x) that runs the Win built-in 21 D of which
the kernel retains 17 D and displays 15 by convention.
In other words, Maxima does not recognize e^ as the scalar exp(x).

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Hi Martin. Thanks. Here, exp instead e^ seems to avoid this issue.

Confirmed. Thank you, filed as SS-4598

Wrote

Same as before, but with a system without a close form for the inverse laplace.

Remember Alvaro, we had some exchange on that Mathsoft Collaboratory.

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Created SS 5346 ... OK SS 6179

Jean

Wrote

Remember Alvaro, we had some exchange on that Mathsoft Collaboratory.

Hi Jean.
I remember that.

Best regards
Alvaro

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Hi Jean.
I remember that.

Try that one with the forcing q(t):= t^0.5 and q(t):= ln(t)
ln(t) expands in term of Ei(,) exponential integral.
How is Maxima will react ?

Jean

ODE_Laplace 2nd [Type 3 Dirac Integral].sm (27 КиБ) скачан 82 раз(а).

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How is Maxima will react ?

Hi Jean. Maxima can't find a close symbolic solution, only find the laplace transform. But this example shows how powerful is the Oscar' routine for inverting numerically laplace transforms. RKFixed and RKAdapt fails and, as you point, only the uni specialized solver dn_GearsBDF seems to solve the equation.

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Best regards.
Alvaro

Hi. This is my attemp to solve a linear equation with polynomial coefficients by laplace method with Maxima. Even don't works, give a solution very close to the numerical RK solver, but I can't see what I'm doing wrong. Any help is welcomed.

Laplace_Maxima5.sm (99 КиБ) скачан 99 раз(а).

Best regards.
Alvaro

Wrote

This is my attemp to solve a linear equation with polynomial coefficients by laplace method with Maxima. Even don't works, give a solution very close to the numerical RK solver, but I can't see what I'm doing wrong. Any help is welcomed.

Can't help Alvaro.
I don't have Maxima. Just posted last minute Oscar InvLaplace.
Don't forget Frobenius for some of those kind variable coefficients.
Works fine Smath, with coefficients helper solve.

Buenos dias Amigo !

I have a portable version of Smath 0.99.7251. The Maxima is under D:\Program Files\Math Tools\SMath Studio\extensions\plugins\44011c1e-5d0d-4533-8e68-e32b5badce41\1.98.7100.23756\
I put the above path into insert->settings, but it show "Cannot find maxima.bat"

Wrote

I have a portable version of Smath 0.99.7251. The Maxima is under D:\Program Files\Math Tools\SMath Studio\extensions\plugins\44011c1e-5d0d-4533-8e68-e32b5badce41\1.98.7100.23756\
I put the above path into insert->settings, but it show "Cannot find maxima.bat"

Did you install Maxima? If not, follow the link in my signature and see the instructions for installing and configuring Maxima. The plugin just provides the interface.