[sympy] Re: GSoc 2018 - Ordinary Differential Equations

[Rahil Hastu]

Can you help me in making me understand what all additions are required for 
the project?The description and the links provided are very confusing and 
moreover there are no links for the part *Lie Groups and symmetry related* 
in the ideas page 
!
 


On Sunday, 4 March 2018 23:50:52 UTC+5:30, Rahil Hastu wrote:
>
> Thankyou Kalevi
>
> On Sunday, 4 March 2018 12:49:24 UTC+5:30, Kalevi Suominen wrote:
>>
>>
>>
>> On Sunday, March 4, 2018 at 7:31:01 AM UTC+2, Rahil Hastu wrote:
>>>
>>> Hello!
>>>
>>> I'm Rahil Hastu a third-year undergrad pursuing Computer Science 
>>> Engineering at PESIT South Campus, Bangalore. I have 2.5+ years of 
>>> experience in Python and C. I'm also familiar with git and GitHub. I'm 
>>> really interested in working in GSoc'18 with Sympy. I went through the 
>>> ideas page and I'm looking forward to work on the *Mathematics Project- 
>>> Ordinary Differential Equation.* I have been consistently exposed to 
>>> the field of Mathematics since my high school, and have taken courses in 
>>> Higher Mathematics including Linear Algebra, Discrete Mathematics, Advanced 
>>> Engineering Mathematics - I, II & III, IV as well as in Computer Science 
>>> including Data Structures and Algorithm Design & Analysis in my Graduation.
>>>
>>> Regarding the project i.e. *"Ordinary Differential Equation" *mentioned 
>>> in the ideas page 
>>> *,
>>>  
>>> *I went through it but some links in it were broken like 
>>> http://www.mathematik.uni-kassel.de/~debeerst/master/ 
>>> gives 404 Error and few others also gave the same issue. 
>>>  
>>> Can someone 
>>> help me in figuring those articles! or the members are requested to fix 
>>> this.
>>>
>>> Thankyou.
>>>
>>
>> Hi,
>>
>> Google currently gives the following link:  
>> http://rubendebeerst.de/master/. It probably leads to the same master 
>> thesis
>> as the broken link originally did.
>>
>> Kalevi Suominen
>>
>

-- 
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 post to this group, send email to sympy@googlegroups.com.
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/sympy/684cc705-9a9e-45d6-bfa5-be47e42026ad%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Re: [sympy] GSoC 2018 - Introduction

[Jason Moore]

Eko,

Welcome. You should start at this document:
https://github.com/sympy/sympy/wiki/GSoC-2018-Student-Instructions. Let us
know if you have questions.

Jason

moorepants.info
+01 530-601-9791

On Mon, Mar 5, 2018 at 2:07 AM, Eko Hardiyanto  wrote:

> Hello,
>
>
> My name is Eko Hardiyanto. I am a student of Informatics Engineering at
> Telkom University, Indonesia. I'm a first year student. I understand
> English in reading but not good in writing / speaking.
>
> I am willing to join GSoC 2018 program and interested in SymPy
> organization.
>
> I know a basic of Python programming language, also basic of Git & GitHub.
> I know the SymPy from this GSoC program and now I am still in understanding
> the SymPy itself.
>
> I am interested in the field of mathematics especially in calculus on
> series expansion.
> I am relatively new to open source and want to contribute to it. How to
> get started?
>
> Thanks.
>
> --
> 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 post to this group, send email to sympy@googlegroups.com.
> Visit this group at https://groups.google.com/group/sympy.
> To view this discussion on the web visit https://groups.google.com/d/
> msgid/sympy/f765a944-542f-4aa0-97a1-b25a0ed7e2e7%40googlegroups.com
> 
> .
> For more options, visit https://groups.google.com/d/optout.
>

-- 
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 post to this group, send email to sympy@googlegroups.com.
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/sympy/CAP7f1Ag69RD4T%3DxHMcCkT8w6qnwMjjm0jeCQsi9rVLBNDgRF%3Dg%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

[sympy] Rewrite trigonimetric terms like sin(Pi*h/2) for integer h as -(-1^(h-1))*mod(h,2)?

[Michael Porer]

Dear all,

first, thanks to all the contributors for providing such a great and free 
tool.

For x-ray structure factor calculations, I end up with huge sums of 
trigonometric terms that I want to simplify knowing that the arguments of 
the trigonometric functions contain summands being multiples of Pi and 
Pi/2. 
In general, the step I am missing is to get from sin(Pi*h/2) for integer h 
to -(-1^(h-1))*mod(h,2) with integer h. The simplification should also 
simplify sin(Pi*h/2+x) to a sum of sin(x) and cos(x) depending on the phase 
Pi*h/2 with h integer. Then I would collect all the sin and cos terms...

Is that doable with sympy? I would be very thankful for a hint how to 
proceed... 

Below is a working code that results in the following expression (h,k,l) 
integer that should be simplified (d real) into something 
f1(h,k,l)*sin(2pi(dh-dk))+f2(h,k,l)*sin(2pi(dh+dk))+...



import sympy as sp
from numpy import *
import matplotlib.pyplot as plt

sp.init_printing(use_latex=True)

u=sp.symbols('u',positive=True)
d=sp.symbols('d',positive=True)

h=sp.symbols('h',integer=True)
k=sp.symbols('k',integer=True)
l=sp.symbols('l',integer=True)

#h=sp.Integer(2)
#k=sp.Integer(1)
#l=sp.Integer(1)

onehalf=sp.Integer(1)/sp.Integer(2)

x=sp.symarray('x',8)
y=sp.symarray('y',8)
z=sp.symarray('z',8)

# Wyckoff 8 h sites

x[0:4]=([u,-u,-u+onehalf,u+onehalf])
y[0:4]=([u+onehalf,-u+onehalf,u,-u])
z[0:4]=([0,0,0,0])

[x[4:8],y[4:8],z[4:8]]=[x[0:4]+onehalf,y[0:4]+onehalf,z[0:4]+onehalf]

s=sp.Integer(0)
for j in range (0,8):
s=s+sp.exp(-sp.Integer(2)*sp.I*sp.pi*(x[j]*h+y[j]*k+z[j]*l))

s=s.subs(u,sp.Integer(1)/sp.Integer(4)-d)
s= (sp.expand_complex(s).simplify())

s


Thank you for reading

Best, Michael

-- 
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 post to this group, send email to sympy@googlegroups.com.
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/sympy/d215e005-aa29-4e20-8bc1-852e508ef685%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[sympy] GSoC 2018 - Introduction

[Eko Hardiyanto]

Hello,


My name is Eko Hardiyanto. I am a student of Informatics Engineering at 
Telkom University, Indonesia. I'm a first year student. I understand 
English in reading but not good in writing / speaking. 

I am willing to join GSoC 2018 program and interested in SymPy organization.

I know a basic of Python programming language, also basic of Git & GitHub. 
I know the SymPy from this GSoC program and now I am still in understanding 
the SymPy itself.

I am interested in the field of mathematics especially in calculus on 
series expansion.
I am relatively new to open source and want to contribute to it. How to get 
started?

Thanks.

-- 
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 post to this group, send email to sympy@googlegroups.com.
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit 
https://groups.google.com/d/msgid/sympy/f765a944-542f-4aa0-97a1-b25a0ed7e2e7%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.