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Aaron Meurer
@asmeurer
apart is the function. You may have to use full=True if it can't factor the denominator.
Sidharth Mundhra
@0sidharth
Is there a function which can break down a Mul which has arguments in terms of +,/ etc into a Mul which has arguments like Add, Rational, Pow etc?
eyJhb
@eyJhb
Can I limit the solve() method, to only show me N solutions? It times out in Jupyter Notebook trying to find solutions, which should be fairly easy. But I suspect that it finds A LOT of solutions, and never finish
Aaron Meurer
@asmeurer
I don't think so, but often when that happens most of the solutions are complex and you only care about real solutions, in which case you can set the variable to be real=True
Mayank-gaur
@Mayank-gaur
Can somebody guide how can I get started on issue #20693. I am a beginner in open source world and would really appreciate any help.
Vishal
@Vishalghyv
Hello all, I am Vishal wanted to contribute to Sympy here is my initial PR please review it sympy/sympy#20726
Yash Patel
@ryuk156
This side Yash Patel here I'm newcomer here can anyone help me how can i start contributing to this community?
Suryam Arnav Kalra
@suryam35
Hi @ryuk156 , you can start with https://github.com/sympy/sympy/wiki/Introduction-to-contributing for starters, and then you can refer to the docs https://docs.sympy.org/latest/index.html. For the later part, refer to https://github.com/sympy/sympy/wiki/Development-workflow.
shardul semwal
@Shardul555

I want the following expression to be simplified in terms of v, I preferred collect() method but it is giving same expression as input .
input expression :(8*c**4*v**2 + 6*c**2*v**4 + 5*v**6)/(16*c**6) + 1
output required:5*v**6/(16*c**6) + 3*v**4/(8*c**4) + v**2/(2*c**2) + 1
through collect():

>>> collect((8*c**4*v**2 + 6*c**2*v**4 + 5*v**6)/(16*c**6) + 1 , v)
1 + (8*c**4*v**2 + 6*c**2*v**4 + 5*v**6)/(16*c**6)

Can anyone suggest better method to do this task

astrojuanlu
@astrojuanlu:matrix.org
[m]
hi all, I'm finding that sin(acos(cos(a) * cos(pi / 2 - 2 * γ))) evaluates directly to sqrt(-sin(2*γ)**2*cos(a)**2 + 1), which is something that I don't want. is there a way to tell SymPy to not perform this sort of simplification?
astrojuanlu
@astrojuanlu:matrix.org
[m]
...found it by chance:
from sympy.core.expr import UnevaluatedExpr
sin(UnevaluatedExpr(acos(cos(a) * cos(pi / 2 - 2 * γ))))
Aaron Meurer
@asmeurer
Or use evaluate=False
2 replies
Arnav Anand
@ArgonArnav
Hello everyone! I am Arnav Anand from India, I have read the instructions for contributing to SymPy, looking forward to working in this organization.
Shatakshi Singh
@shatakshisingh24

Hello everyone!
I am Shatakshi, a third-year Computer Science undergraduate student at Mody University, India.

I have previously worked on research papers so I am comfortable with python and theoretical concepts of Machine Learning and their implementation.

This is the first time I will be contributing to a big project with so many contributors. I have read the instructions to contribute. It will be really helpful if I can get some clue on how to start contributing to this kind of projects.

Suryam Arnav Kalra
@suryam35
@shatakshisingh24 you can start with the easy to fix aka good first issues and get a understanding of the codebase.
Shatakshi Singh
@shatakshisingh24
Thanks @suryam35 , on it!
Craig Russell
@ctr26
Evalf isn't evaluating my integral even with .evalf(subs=dict) any thoughts on why?
I ask because I'm trying to parallelize the computation of my integral over a range
Currently I'm lambdifying it using mpmath as it returns nan with numpy
But I can't get dask to serialise the lambda function to make it parallel
Aaron Meurer
@asmeurer
There can be issues parallelizing things with SymPy because of serialization bugs.
jicky94
@jicky94
Hi everybody, i have a question regarding nonlinsolve'. When i used it for my system of equations (some of which are non linear), i get solutions in terms of other unknown and not only in terms of the parameters. I checked the documentation but did not see the relevant options. What am I doing wrong? If anyone could help me, that would be fantastic. In other words i am not able to get explicit solutions. I could copy paste my code but it does not seem the right place to do that :) many thanks and have a nice day
Craig Russell
@ctr26
There can be issues parallelizing things with SymPy because of serialization bugs.
@asmeurer K so, the best way to do this is by serialising a function that wraps lambidfy rather than creating your lambidfied function first then trying to serialise that. Thi is working for me in task nicely
def numba_func(consts):
model = sp.lambdify(tuple(consts.keys()),integral,"mpmath")
return model(*tuple(consts.values()))

out = client.map(numba_func, consts_list)
result = client.gather(out)
Aaron Meurer
@asmeurer
I don't know how well lambdify functions serialize because they are dynamically created
But other than that, they do not involve SymPy expressions, so they might actually serialize better
Craig Russell
@ctr26
The above code works well with dask as the lambification runs on the workerrs
Aaron Stiff
@AaronStiff
I'm investigating #20762, and I'm pretty sure it's an issue with ANTLR. I've been looking at LaTeX.g4 to see how it handles subscripts, and everything seems correct. The only potential problem I've found is this:
subeq: UNDERSCORE L_BRACE equality R_BRACE; supeq: UNDERSCORE L_BRACE equality R_BRACE;
Not sure if this could be causing the problem, but could anyone familiar with ANTLR comment on whether or not supeq should be using CARET instead?
Sayandip Halder
@sayandip18
I was going through plot.py and came across the check_arguments() function here. Though I sort of understand how it works, I still don't understand it's purpose. The docstrings aren't much of a help either. Can someone tell me why the function behaves that way?
10mayje
@10mayje
hello, I am Tanmay Mondal a second-year student of nit Durgapur, West Bengal, India. I am expressed in python, Django. How can I get started?
Aaron Meurer
@asmeurer
@AaronStiff I think that issue is unrelated to parse_latex. It is parsing the expression right. python() just doesn't print it right.
Craig Russell
@ctr26
Anyone know why this simplfies to 0, it doesn't in mathematica?
import sympy as sp
from sympy.concrete.summations import Sum

sp.Derivative(Sum(sp.exp(x*sp.sin(n/m)),(n,1,m)),x).simplify()
Craig Russell
@ctr26
This works fine:
Sum(sp.Derivative(sp.exp(x*sp.sin(n/m)),x),(n,1,m)).doit()
Aaron Meurer
@asmeurer
Looks like it is a bug
Something weird is happening here
>>> Sum(exp(x*sin(n/m)),(n,1,m))
Sum(exp(x*sin(n/m)), (n, 1, m))
>>> Sum(exp(x*sin(n/m)),(n,1,m)).doit()
Piecewise((m*exp(c3_), Eq(exp(c2_), 1)), ((exp(c2_) - exp(c2_*(m + 1)))*exp(c3_)/(1 - exp(c2_)), True))
Alex Nguyen
@rxng8
Hi I'm new to sympy. I hope I can go with sympy and contribute from now on
I have a few questions: when we rebuild the repo after making changes, does the repo get re-install again or only the modified part get installed? How do we run test on a single test case? How do we log the info from the test case when testing (is there any params when build that has to be added?). Sorry for the long questions!
Aaron Meurer
@asmeurer
You don't have to build SymPy because it is pure Python. If you installed from git, you will have to install again unless you did a pip install -e or setup.py develop. Although I personally just run Python directly from the sympy directory. That does not require reinstalling, as it will just import the development version of SymPy directly.
To run the tests on a single case, you can pass in the file name like ./bin/test test_solvers.py, and use -k to select a specific test like ./bin/test -k test_whatever
I'm not sure about the log question. The output is printed to the screen. You don't have to do anything special to run the tests.
Alex Nguyen
@rxng8
Well that's great helps, thanks a lot !
Hi, can someone tell me how can we add a new function in sympy, beacuse on directly adding, and then calling in terminal gives NameError and says that function called is not defined. Thanks!
Naveen Sai
@naveensaigit
@hyadav2k If you open python in the same working directory as the repo you clone, you can import the sympy you made changes to without any problems
Craig Russell
@ctr26

Looks like it is a bug

Thanks aaron!

Nisarg Chaudhari
@Nisarg-Chaudhari
Hello everyone, I'm Nisarg Chaudhari, a second year computer science undergrad, studying at BITS Pilani Hyderabad Campus, India. I am familiar with python and made some personal projects with it (mainly small games with pygame). I would like to contribute to SymPy. This is my first time contributing to open source, currently going through "Introduction to contributing" in sympy wiki. Is there anything else I need to know to get started?

@hyadav2k If you open python in the same working directory as the repo you clone, you can import the sympy you made changes to without any problems

Thanks for sharing @naveensaigit!

Naveen Sai
@naveensaigit

@hyadav2k If you open python in the same working directory as the repo you clone, you can import the sympy you made changes to without any problems

Thanks for sharing @naveensaigit!

No problem!

Aaron Stiff
@AaronStiff
I'm just running some tests in the printing module, but even without making any changes to any files, pytest` is reporting 8 failed tests. Is this normal?
Thomas Aarholt
@thomasaarholt
What are the failures?