Sympy and symbolic differentiation

I am currently porting a code from mathematica to python. As is commonly known, code which is a few tens of lines in a higher level language becomes twice or thrice that in a lower level language. While there are convenience functions in mathematica and python for almost everything imaginable and needed by a student/physicist (except for a theta function!), the one thing that sets mathematica apart from everything else is it's ability to do symbolic math. The fact that the language was built around this (is it?) probably lends to this but nevertheless, it's one of the things that I'm having the toughest time reimplementing in python. I've been working with sympy, picking up the pieces along the way but I've hit a roadblock for the time being. I'm not able to differentiate an expression that contains a theta function! I'll prolly have to rewrite the expressions so that it'd be easier to work in python i.e do sym diff.

The other interesting thing that I've come across is the use of lambda in defining functions. Other than making the code look cleaner and more understandable, it's cleared up a couple of errors I have having in the earlier case, when i was using def to define functions. I am yet to grasp the full power of this but let's see where this takes me.

But in all honesty, implementation based on an algorithm > reimplement based on a code in another language > rewrite other people's code to make things work!

Popular posts from this blog

Farewell to Enthought

I started my professional career at Enthought , at the Pune office in India, on Feb 29, 2016. Over the course of eight long years, I spent time at the Austin office in the US, the Cambridge office in the UK, and I worked remotely from India. I was let go on March 27, 2024 . I had an unbelievably great time. I had three amazing mentors - Pankaj Pandey, Senganal Thirunavukkarasu, and Mark Dickinson. Pankaj mentored me in my first year at Enthought. I started paying attention to the craft of software after working with him. Senganal started mentoring me in my second year at Enthought, and continues to mentor me, even after the both of us have moved on from Enthought. He instilled professionalism in me, ensuring that the code I wrote produced precise scientific results, and that I tackled the known unknown aspects of a project first, to ensure timely communication about project progress. I was eager to manage people at the time and Senganal made me realize that I didn't want to manage ...
Read more

Arxiv author affiliations using Python

So, I wanted to get author affiliation information from papers on arXiv. arXiv provides with an API to bulk query their database and get information. Following that, I look for the attribute 'arxiv:affiliation' in the html data. Here's the code - import urllib from BeautifulSoup import BeautifulStoneSoup   url = 'http://export.arxiv.org/api/query?search_query=all:astro&start=0&max_results=1000'   data = urllib.urlopen(url).read() soup = BeautifulStoneSoup(data) #print(soup.prettify()) #list = soup.findAll('arxiv:affiliation') #for i in range(len(list)): #        print list[i].contents   test = [tag.string for tag in soup.findAll('arxiv:aiffiliation')] Now, the problem I'm having is that I'm getting affiliation of all authors which I want to split into sets of affiliations of authors of a paper, which I'm stuck on at the moment. Once I get that part, I can move on to the next part of this pet project, displaying these...
Read more

Elementary (particle physics), my dear Watson

Ground Control to Major Tom:  Shruti Patel checking in. Since my dear friend and fellow-physicist Rahul Poruri is homeward bound, and shall remain there for a week, I'm stepping in to continue his tradition of daily posts to Astronut . Even as I write, I'm not quite sure what this post is going to be about, so please forgive me for occasional rants and digressions.  By the way Rahul, I totally resent you for the name of this blog- I'm never going to start my own blog because there's no way I'll come up with a name as cool as Astronut! For now, I shall try and be happy with being a guest writer! Before I begin, a little bit on who I am and what I do; so that you can trust that my general views on science- particle physics in particular- are not entirely baseless. I graduated with a masters in Physics from IIT Madras in July this year, and I'm currently working towards (an eventual) PhD with the Theory Group at the Deutsches Electronen-Synchrotron (DESY)...
Read more