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##### Activity
• Jul 02 17:52

anutosh491 on hyperbolic_functions

Restructured tests for nseries … (compare)

• Jul 02 13:59

anutosh491 on hyperbolic_functions

Improved Code for Bi-directiona… (compare)

• Jul 02 11:26

anutosh491 on hyperbolic_functions

Fixed Bi-directional limit cases (compare)

• Jul 02 06:50

anutosh491 on hyperbolic_functions

Fixed bi-directional limit case… (compare)

• Jul 02 04:43

anutosh491 on hyperbolic_functions

• Jul 02 02:48

anutosh491 on hyperbolic_functions

Implemented series for function… (compare)

• Jul 02 01:33

anutosh491 on hyperbolic_functions

Implemented taylor_term method … (compare)

• Jul 01 16:11

• Jul 01 12:47

Refactored Leading Term method … Fixed leading term methods for … Fixed leading term for trigonom… and 1 more (compare)

• Jul 01 10:33

• Jun 29 10:28

Added expand to log rewrites (compare)

• Jun 29 09:23

updated test for asin,atan,acot… (compare)

• Jun 27 12:01

removed wrong test (compare)

• Jun 27 11:21

Modified test (compare)

• Jun 26 00:22

Fixed leading term for acos/ase… (compare)

• Jun 25 09:43

anutosh491 on series_for_arg

Updated code (compare)

• Jun 24 13:33

Improved code quality (compare)

• Jun 22 14:25

Fixed code quality (compare)

• Jun 22 14:17

• Jun 22 10:02

Fixed Failing tests (compare)

ronanpaixao
@ronanpaixao
@asmeurer Filed #15182
Bunnyyyyy
@Bunnyyyyy
Bunnyyyyy
@Bunnyyyyy
Malkhan Singh
@Malkhan52
Bunnyyyyy
@Bunnyyyyy
Malkhan Singh
@Malkhan52
@Bunnyyyyy I gave a talk in my institute (NITR) last week on How to start contributions in open source projects, ping me I can provide link of that slide.
Bunnyyyyy
@Bunnyyyyy
@Malkhan52 Sir, what do you mean by ping ?

@Bunnyyyyy there is a link attached to the top of this chat with information for people new to contributing: https://github.com/sympy/sympy/wiki/Introduction-to-contributing

"ping" means attract one's attention and in this case probably suggests that you send a private message to the person

Bunnyyyyy
@Bunnyyyyy
Thank you :)
Jason K. Moore
@moorepants
Is there something similar as @doctest_depends_on for normal test functions?, i.e. @test_depends_on('numpy') or something like that?
Kalevi Suominen
@jksuom
I don't think that there is. The issue is handled in code as e.g. in test_sympify:
numpy = import_module('numpy')

def test_issue_10295():
if not numpy:
skip("numpy not installed.")
Jason K. Moore
@moorepants
@jksuom Thanks. We should turn that into a decorator.
Ayushman Koul
@ayushmankoul
Hello @jksuom I hope you are doing well. As asked by you to go through how matplotlib works I went through it to know how to write code for plotting line segments.Now coming back to issue, if I am not wrong I need to write a new method for plotting line segment and triangles inside class Plot in plotting/plot module ? Please guide me so that I can proceed further to it.Thanks
Kalevi Suominen
@jksuom
It seems that most objects to be plotted are subclasses of BaseSeries.
Micah
@micahscopes
Hi there, I'd like to understand how best to compose multilinear maps of symbolic elements in sympy
so far I've been doing it the hard way
which is to make lists of multivariate polynomials, iterating over them and substituting, then sorting
I'm still a kindergartner at tensor algebra
but I'm learning
it seems like some kind of tensor representation would be ideal for this
so the specific objects I'm interested in currently are finite k-algebras, which I'm "harvesting" from sage
the core of each finite k-algebra is its product, which is a "bilinear map" $V \times V \rightarrow V$
so in sympy, I'm representing these as lists of multivariate expressions
Micah
@micahscopes
this is a very simple way of representing these products, but when I want to compose these functions, it makes things difficult
Micah
@micahscopes
An example: say I have a (real) vector space $M$, whose vectors represent matrices in some finite dimensional real matrix algebra, and a (real) vector space $C$, whose members represent complex numbers, then I have a map $f:M \times M \rightarrow M$, the matrix algebra product, and another map $g:C\times C \rightarrow C$, the product of complex numbers.
Now, I'd like to compose these products to make a matrix algebra over the complex numbers
Micah
@micahscopes
so I know from wikipedia that formally, what I'm trying to do is some kind of tensor product... I think a "tensor product of algebras" (https://en.wikipedia.org/wiki/Tensor_product_of_algebras). but while it's easy enough to comprehend a tensor product of vector spaces, I'm still trying to understand how to apply this in sympy
Micah
@micahscopes
ahh, I'm reading now that this is also called "base change"
Kalevi Suominen
@jksuom
@micahscopes How are you planning to represent the (bilinear?) map $f: M \times M \to M$?
Bjorn
@bjodah
Micah
@micahscopes
@jksuom currently I've just been making a list of symbolic multivariate polynomial expressions. The symbols are the components of the two input vectors, E. G. f([u_1, u_2,... , u_n], [v_1, v_2,... , v_n]) would return a list of polynomials of terms from the u and v lists.
In Sage, you can construct algebras over a SymbolicRing, then take the product of two symbolic vectors and convert the result to a list of sympy expressions
(after that I'm using the glsl code printer in sympy)
Micah
@micahscopes
Kalevi Suominen
@jksuom
A bilinear map like $f: M\times M \to M$ corresponds naturally to a rank three tensor.
A (1, 2) -tensor actually, I think.
Micah
@micahscopes
@jksuom that makes sense... so if I figure out how to represent my algebras as (1, 2)-tensors, I should also be able to find a way, using tensor algebra, to more easily compose them
Kalevi Suominen
@jksuom
I think that is true though I'm not sure what you mean by 'compose'.
Micah
@micahscopes
I'm not sure either, I don't think "compose" is the mathematically correct term, but I'd like to do multiple "base changes"
I'd like to be able to construct some of these division algebras: https://core.ac.uk/download/pdf/25253839.pdf
Kalevi Suominen
@jksuom
Those tensor products of algebras can be represented by products of tensors (taking proper care of the indices).
Ayushman Koul
@ayushmankoul
@jksuom As you pointed if I am not wrong we need to amend subclasses of BaseSeries containing 2D lines series.Please can you tell me how should I proceed further on this issue ?
Kalevi Suominen
@jksuom
You could probably start by adding methods that would create instances of List2DSeries to some geometric classes such as Segment and Triangle, and also Polygon. (Those could then be appended to a suitable Plot object for showing.)
Micah
@micahscopes
@jksuom I think I'm starting to get some intuition for this idea
Kalevi Suominen
@jksuom
The components $a_{ijk}$ of the tensor associated with the bilinear product in an algebra can be found as follows. If $(e_i)$ is a basis of the algebra, then the components are the coefficients of the pairwise products $e_i e_j = \sum_k a_{ijk} e_k$.
Kalevi Suominen
@jksuom
For example, if $\Bbb{C}$ is considered as an $\Bbb{R}$-algebra with basis $(1, i)$, then $a_{110}=-1$ is the coefficient of $1$ in $ii$ and $a_{111}=0$.
Micah
@micahscopes
@jksuom !thank you so much!
basically then, to construct the tensor of a finite k-algebra, I just need to get the coefficients in k of pairwise products of basis elements of the algebra
Micah
@micahscopes
I think I need to really play with the summation notation