tag:blogger.com,1999:blog-2591942684384994852024-03-19T09:57:09.841+05:30Scientia potestas est. - Knowledge is power.ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.comBlogger112125tag:blogger.com,1999:blog-259194268438499485.post-67636394446247916612016-12-03T14:17:00.003+05:302016-12-03T14:26:43.176+05:30Getting Started With STM32 and Simulink
The STM32 microcontrollers are powerful and full of awesome features but as anyone who has tried to work with the STM32 microcontrollers will know, setting them up and programming them can be a little difficult. I recently bought myself the STM32F4 Discovery development board and after trying a lot of new things, managed to setup a working development environment. I initially set up my ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-45902221949210248652016-06-16T15:41:00.000+05:302016-06-16T15:41:37.619+05:30New Website and Blog
As I mentioned in an earlier post (exactly a year ago! :D) I have my own website now. When I first bought the domain name and hosting package I opted to get a shared hosting server where I could build my own website using Wordpress. However, it never really satisfied me. I got a decent looking website up and running, but I had to work with the constraints of the Wordpress CMS. ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-52700578964120439642016-03-30T11:31:00.001+05:302016-03-30T11:31:49.925+05:30Unsupervised Learning: Self Organizing Maps
Most machine learning techniques like logistic regression, linear regression, and neural networks do something that is called supervised learning. This means that we need to supply examples of "correct" data to the machine learning algorithm for it to learn the patterns in the data. The goal of unsupervised learning is to automatically find clusters of similar data in a huge unlabeled set of ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-43913065686181581292016-03-22T15:37:00.000+05:302016-03-23T08:09:50.352+05:30Machine Learning Part 2: Implementing Multi Class Logistic Regression
In my last post on machine learning I talked about how to implement simple linear regression in Python. This time I am going to implement logistic regression. This technique is used to classify input data into one of several classes.
First let's take a look at two class regression.
Let's have a set of input vectors $\{x_1, x_2, ... , x_N\}$ and a set of targets $\{t_1, t_2, t_3, ..., t_Nashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-65176553109062618282016-02-27T01:54:00.000+05:302016-02-27T01:54:47.381+05:30My First Build of BB-8
Being a robotics person, the part of Star Wars: The Force Awakens that gave me the most delight was BB-8! The cute little droid who rolls along on a sphere. The moment I saw it on screen I knew that I had to build it! This blogpost documents my entire build process.
I decided that the first thing I should do is come up with a good control mechanism. The first thing I thought of was a pendulum ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-39255725782991024362015-11-20T22:22:00.000+05:302015-11-20T22:22:50.615+05:30Prime Spirals in Python
I watched this really fascinating video on prime spirals recently and decided to see if I could write my own code to generate them. It's not terribly efficient but it works! Code is on github! :D
ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-52766818778623647182015-11-20T00:18:00.000+05:302015-11-20T00:18:35.837+05:30Machine Learning: Implementing Linear Regression and Gradient Descent in Python
It's been a while since I went through Andrew Ng's Machine Learning course on Coursera. The course is very good at introducing the basic concepts but it lacks the depth of knowledge that I need if I really want to understand how to implement and use some of the algorithms on my own. So I decided to work through a more difficult textbook on machine learning. One of the first things I decided to ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-6987586308109906782015-11-15T19:08:00.000+05:302015-11-15T19:22:53.022+05:30The One Thing that my College Gets Wrong About Exams
I'll be honest. Despite it's shortcomings, many of the courses that are offered actually do contain material that I find interesting. In fact, when you're learning something at the level of a college course, there are few subjects that aren't interesting. It's like Richard Feynman said; everything is interesting if you go deep enough into it. My biggest complaint about the system isn't theashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-24503633215271407962015-10-15T14:32:00.000+05:302015-10-16T14:32:40.442+05:30Simulating a Double Pendulum in Mathematica
I've been playing around with Mathematica's Non-Linear Control Systems toolbox over the past few days and it's been brilliant! One of the first systems that I tried to simulate is the double pendulum since it's such a commonly used sample problem in non-linear controls.
The first step is to write down the total kinetic and potential energies of the system and find the Lagrangian. Once you ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-52858574429462628422015-10-11T09:38:00.000+05:302015-10-11T09:38:30.113+05:30Simulating Mechanical Systems in Mathematica
I've been trying a lot of different software for simulating mechanical systems for my project. By far, the most fun I've had is when I was simulating it on Mathematica. Mathematica is a seriously cool piece of software. I got a simulation of the simple pendulum up and running almost 3 times faster than I did when I was working with Python and Matplotlib. Although, to be fair, the time I did it ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-37540126527110273622015-10-09T20:32:00.000+05:302015-10-09T20:32:01.769+05:30Movie Review - Interstellar
Interstellar is a movie that I had been looking forward to for quite a while. After watching the movie I started going through a lot of the movie reviews that people started posting. I was quite disappointed to see so much negativity and nitpicking directed towards the movie.
The movie is set in a dreary post apocalyptic earth ravaged by dust storms. Food is scarce and blight is ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-35554770150890003782015-10-08T01:40:00.000+05:302015-10-08T01:40:54.914+05:30The Magical Euler-Lagrange Equation and the Calculus of Variations
I've been learning a lot about simulating and controlling mechanical systems for one of my projects. Of all the math that I learned, the most amazing was the Euler-Lagrange equation.
$\frac{d}{dt} \frac{\partial L}{\partial \dot{q_i}} - \frac{\partial L}{\partial q_i} = Q_i$
The overarching theme of the control systems that I've been reading about is optimality. And wherever we need ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-89503138991948954722015-10-05T23:09:00.000+05:302015-10-05T23:09:29.728+05:30Movie Review - Real Steel
Two weeks ago I discovered pure awesomeness in the form of Battle Bots. I spent my whole evening watching every episode of the 2015 season. Seeing my excitement, my friend suggested that I watch this movie called Real Steel which was released in 2011.
The movie is set in a future where human boxing is outlawed (Good!). Instead people watch insanely cool robots go all out against each ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-1694803583629514612015-08-28T17:11:00.000+05:302018-10-23T10:27:41.431+05:30Book Review - The Martian by Andy Weir
Fantasy books were my gateway drug into the world of reading. Starting with Harry Potter, The Inheritance Cycle and the Lord of the Rings, fantasy was a staple of the steady diet of books. Then I discovered Famous Five, Secret Seven and other children's adventure novels. I started reading science fiction quite late into my life. Although I read a few books here and there I didn't really ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-90035292600362890992015-08-18T00:25:00.000+05:302015-08-18T00:29:16.605+05:30Dung Beetles are Extremely Cool
I've noticed little bugs scurry across the road quite a lot during my time at this college. Most of the time I've been too busy to actually go down and examine these bugs. Today, when I saw one of these critters crawling beside the road I decided to take a closer look.
What I found was the Dung Beetle in the process of rolling a ball of dung and trying to find a nest. Dung beetles are ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-49407632588379425242015-07-28T09:57:00.001+05:302015-10-05T15:29:04.695+05:30Creating a Simple Bot using the Telegram Bot API
So Telegram recently released an API for creating bots on Telegram! It's quite cool. Already, people have released nice Python libraries for it. For this bot I'm using one of them.
I decided to create a simple Telegram bot that I can use to control the music on my laptop. It's a testament to the power and simplicity of Python and the convenience of the linux terminal that it only took me an ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-45391870081358197262015-07-28T09:52:00.001+05:302015-10-05T21:41:34.596+05:30Movie Review - Whiplash
Note: This post may contain spoilers.
I used to watch sci-fi and animated films exclusively but now every once in a while I watch a random movie just for the fun of it. Yesterday that random movie turned out to be Whiplash - a movie about an aspiring drummer and his well intentioned but abusive mentor.
I loved the movie but I disagree with the opinions of Terence Fletcher. There is a ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com1tag:blogger.com,1999:blog-259194268438499485.post-65738145525097890532015-07-18T20:00:00.001+05:302015-07-18T20:15:24.799+05:30Maker Faire Singapore
The
day before yesterday I found out that there was a Maker Faire going on
in Singapore this weekend! I immediately scrapped all my other plans for
the weekend to get there. It was definitely worth it. I owe a lot to
the maker movement. It's what got me interested in engineering and I
think it's a big part of the reason I am the person I am today!
The
highlight of the Maker Faire was ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-6944957819802496012015-07-18T19:34:00.000+05:302015-07-18T19:34:43.982+05:30Why Self-Driving Cars are the Future of Personal Transport
So Google's self driving cars are getting really good at self driving. A lot of people I know are skeptical about self driving cars. Some say that they will never use them because they just love to drive. I think that once self driving cars are actually on the road, they won't have a choice.
From everything the the testing of the self driving cars have shown so far, they seem to be much safer ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-46767929142008948642015-07-03T10:56:00.001+05:302015-07-03T11:03:09.923+05:30Terminator Genisys – Review
I watched the movie a few days ago. And I thought I’d write down some thoughts I had about the movie.
First of all, I have to admit that although I roughly know what happens in the earlier movies I have only watched one of the previous three movies.So this is the first Terminator film the I’ve watched fully.
For me, the movie was just OK. Nothing spectacular. Visual effects were nice ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com021 Lower Kent Ridge Road, National University of Singapore, Singapore 1190771.2966426 103.776393900000021.2331441 103.69571290000002 1.3601410999999999 103.85707490000001tag:blogger.com,1999:blog-259194268438499485.post-15857694429177885082015-06-22T06:40:00.001+05:302015-07-03T11:02:17.771+05:30Another Weekend in Singapore
Now I’m working for a lab I guess I have a good idea of what working a 9 to 5 job will be like. I barely have time to do anything on weekdays. Free time has become a very precious resource. So weekends are the only time I get to actually do stuff. And most of the time, after a busy week all I feel like doing on the weekend is relax.
I’ve started going to the movies almost every week now. I ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-29150087628668502912015-06-20T20:55:00.001+05:302015-10-05T15:32:29.843+05:30Using IFTTT for blog syncing.
So since I decided to keep both my blogs running in parallel, I’ve only posted two blogposts and I’m already starting to find it annoying to update both blogs every time I get a new idea for a post. So I decided to try out this thing that I signed up for a long time ago, but never really used till now. IFTTT (IF This Then That). It’s a web service that allows you to automate your social media ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-19204776814461229362015-06-19T09:39:00.001+05:302015-10-05T15:32:40.378+05:30Analysing sound in Python
I'm
trying to build a simple word recognition system in python. As a first
step, I needed to find a way to get audio sample data from my microphone
and store it in a numpy array in Python. After a lot of searching and
experimenting I finally found a library that works well for this task: pyalsaaudio.
This small piece of code records roughly two seconds of audio from the default ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-80422415744663776682015-06-16T08:57:00.001+05:302015-06-16T08:57:46.840+05:30I have a new website!
So it's summer holidays again! This time I'm spending my holiday as a research intern at NUS in Singapore. I love the labs here! They're absolutely amazing. I got an opportunity to see one of those huge KUKA robotic arms up close. Me and my friends are working on a four legged robot that uses a lot of compliance and underactuation. It's been quite a fun experience. Singapore is a really nice ashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0tag:blogger.com,1999:blog-259194268438499485.post-77654615118698875562015-02-02T17:22:00.000+05:302015-10-05T15:33:20.435+05:30VGA Output from an FPGA
So after the simple 8 bit counter on the fpga I decided to get started with generating VGA output from my FPGA. Because that seemed to be a reasonably simple yet really cool looking project. Initially I thought I'd go the cheap way and solder up my own VGA circuit. But I just ended up wasting a lot of time and effort to get a really substandard circuit that would die on me all the time. So I gotashwinhttp://www.blogger.com/profile/03557389610385021930noreply@blogger.com0