Getting coords of multivector

[ingodahn]

How can I extract the coordinates of a multivector for further processing (e.g. as reals)?

Example:
Given a multivector v=e_1+2*e_2+3*e_3 how can I calculate from it the list v1=(1,2,3) for further calculations, like getting math.sin(v1[1])?

[Greg1950]

Suppose one has a multivector *M *. The command *M.blade_coefs() * will return a list of the coefficients in the basis blade expansion of *M*. *Example.* E3 is a GAlgebra model of Euclidean 3-space. * M = E3.mv('M','mv') # instantiate a generic multivector M* * gprint(M) # output M * * gprint(M.blade_coefs()) # output the coefficients in the basis blade expansion of M* The function *gprint* may be unfamiliar to you as it is not included with GAlgebra even though it was written by that program's original author (Alan Bromborsky). *gprint* produces typeset quality output, which I find very beneficial when dealing with mathematics. To the best of my knowledge, GAlgebra (website https://github.com/pygae/galgebra) has not been maintained for the last three years, for GAlgebra has been stuck at version 0.5.0 throughout that period. I found a good number of bugs in a couple of GAlgebra 0.5.0 's modules, and believe I have managed to eliminate them. Those corrected modules are not available from the GAlgebra website, but they may be acquired from the website of Alan Macdonald (author of *Linear and Geometric Algebra* and its sequel *Vector and Geometric Algebra*). To get gprint and those corrected modules: 1. Go to http://www.faculty.luther.edu/~macdonal/laga/index.html . 2. Click on the *GAlgebraPrimer* link to download the GAlgebraPrimer.pdf file (link takes you to http://www.faculty.luther.edu/~macdonal/GAlgebraPrimer.pdf ). 3. On page 3 of that PDF file, click on the *GAfiles.zip* link to download that zip file (link is to http://www.faculty.luther.edu/~macdonal/GAfiles.zip ). 4. GAlgebra Primer has instructions as to which files in GAfiles.zip need to be placed in your /site-packages/galgebra folder. I hope you find the above information of use.

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On Thu, Mar 9, 2023 at 2:44 AM Ingo Dahn ***@***.***> wrote: How can I extract the coordinates of a multivector for further processing (e.g. as reals)? Example: Given a multivector v=e_1+2*e_2+3*e_3 how can I calculate from it the list v1=(1,2,3) for further calculations, like getting math.sin(v1[1])? — Reply to this email directly, view it on GitHub <#483>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AG2OCIEODOD66YY6NZGERTLW3GKAJANCNFSM6AAAAAAVUZKI7Q> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[ingodahn]

Thanks, this is indeed very useful. I'd suggest adding this example to Introduction to using GAlgebra — galgebra documentation <https://galgebra.readthedocs.io/en/latest/tutorials/algebra.html>