Re: [sympy] SymPy Wedge Product Question

['Carsten' via sympy]

HI,

 

I almost do not follow this mailing list since a while but I just stumbled on this thread.

 

Several years ago I had some trouble in learning to calculate with differential forms and and back then the sympy support was not sufficient for me (dont know about the current state). Thus I implemented my own package (on top of sympy): "pycartan" [1]. As it is typical for research code, it served its purpose (doing some calculations related to control theory), and after this it lays around without attention (and with almost no docs).

 

Maybe it is still useful for some people. Unfortunately the "best" documentation available for this package is the collection of unittests [2].

 

If there is serious interest in this package I might be motivated to put some time/effort in it. For reaching out I suggest to contact me via [3].

 

[1] https://github.com/TUD-RST/pycartan/

[2] https://github.com/TUD-RST/pycartan/blob/master/pycartan/tests/test_pycartan.py

[3] https://wwwpub.zih.tu-dresden.de/~knoll/en/

 

Best,

Carsten

 

Gesendet: Dienstag, 26. März 2024 um 19:37 Uhr
Von: "Tomás Silva" <tomassrsi...@gmail.com>
An: "sympy" <sympy@googlegroups.com>
Betreff: Re: [sympy] SymPy Wedge Product Question

I'm facing a similar issue. I think SymPy is not treating correctly the sum of (co)vectors.

In this question I exemplify my issue https://stackoverflow.com/questions/78226587/sympy-manipulation-of-wedge-products
Could anyone shed a light on how to properly sum differential forms?

Thanks in advance,

Tomás

On Monday, March 25, 2024 at 12:06:45 AM UTC Samith Kavishke wrote:

I could not find the problem that you are stating in the video lecture
 

On Thursday, March 21, 2024 at 9:21:52 PM UTC+5:30 kushwahas...@gmail.com wrote:

Can you please specify what purpose you are using it for. I do not know its use yet but would like to get back to you after researching on its usage .

 

_ _ _ _ _ _ _  

Shishir
 

On Tuesday 19 March 2024 at 22:54:42 UTC+5:30 giovanni...@gmail.com wrote:

Can anyone help me with this, please?

 

 

On Mon, Mar 11, 2024, 06:06 Giovanni Sutanto <giovanni...@gmail.com> wrote:

Hi SymPy Community,

 

I am now trying to understand what happens when I perform WedgeProduct operations on SymPy.

 

So, I understand how to use the SymPy's Wedge Product to some extent, i.e. I was the one who responded to the question on Stack Overflow: https://stackoverflow.com/questions/76981303/computing-the-wedge-product

 

However, when I have:

'''

my_matrix = Matrix([[2, 0, 5], [0, 7, 0]])

r2_r_oneforms = R2_r.base_oneforms()

r2_r_vectors = R2_r.base_vectors()

 

cols = [None] * 3

for j in range(3):

  cols[j] = 0

  for i in range(2):

    cols[j] += my_matrix[i, j] * r2_r_vectors[i]

 

cols_wedge_product = WedgeProduct(*r2_r_oneforms)(*cols)

print('cols_wedge_product = ', cols_wedge_product)

'''

What I get is:

cols_wedge_product = -42

 

Where does the number -42 come from?

 

On the other hand, if:

my_matrix = Matrix([[1, 0, 1], [0, 1, 0]])

I get:

cols_wedge_product = 0

What computation leads to 0 here?

 

Can any of you please explain it, e.g. in the terms of the example in the video lecture https://youtu.be/xRf9-hdxB0w?feature=shared&t=2961 ?

 

Thanks so much in advance for your time!

 

 

Best Regards,

 

Giovanni

 

--
You received this message because you are subscribed to a topic in the Google Groups "sympy" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/sympy/-MAK_y6-9Yc/unsubscribe.
To unsubscribe from this group and all its topics, send an email to sympy+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/b7fb6f7e-232d-4414-b938-1cdbab35cd76n%40googlegroups.com.

 

--
You received this message because you are subscribed to the Google Groups "sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/fabd8204-3f56-4aed-b8e4-065f2d361ba0n%40googlegroups.com.

--
You received this message because you are subscribed to the Google Groups "sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/trinity-812a58cf-6db1-4756-8560-2340e33432c6-1714293450672%403c-app-gmx-bap02.