sagargv

It seems to me that the major issue that Cardboard solved is navigation in a 3d environment. Using a mouse or controller to move around, aim, and shoot in a 3d world is natural to those of us who play 3d games. But, these actions aren't intuitive at all, unlike looking around while wearing a VR headset.

A few months ago, Amazon's competitor Flipkart started asking users to order via the app rather than through the browser. That's when a lot of my friends and I switched to Amazon. I never really understood the reason for insisting on ordering via the app.

Apps don't have a good way to convey that they are using HTTPS, so I don't like the idea of entering my credit card details in an app. Most internet banking gateways in India aren't yet mobile optimized, so that's inconvenient too. (Internet banking is a popular alternative to debit cards in India; merchants re-direct users to their bank's website where users can login and agree to paying the merchant. It's actually a lot more convenient than credit cards because you only have to remember your bank account's username and password.)

They seem to have run out of ips/servers and aren't accepting new users. So, I wouldn't host anything serious with them just yet.

How does Amazon implement instances like t2.nano? If there are 40 t2.nano instances on a quad core physical machine, what happens when all the users want 100% CPU, even if it's only for 10 minutes? Are instances automatically migrated to a different physical machine if this happens?

AMD might support CUDA soon - http://www.anandtech.com/show/9792/amd-sc15-boltzmann-initia...

I wrote a bookmarklet for this a year ago and have since been using it every day: http://www.sagargv.com/proj/flathn/

Where was twitch.tv hosted before the acquisition? Bandwidth on AWS would've costed a bomb.

My university uses a HTTP proxy too. The proxy makes connections only on ports 80 and 443. So, OpenVPN on port 443 is pretty much the only option. Wish Google Hangout would work over HTTPS.

I like the idea of breathing more life into C. Look at what's happened to C++. These days, when I need the efficiency, I prefer coding in C to C++. But I'm not sure Cello is the right way to make C better. If you're starting a new project, what's wrong with a struct that has an array and length of the array? Cello seems to break the simplicity of C and its memory model.

KiCAD files:

https://dl.dropboxusercontent.com/u/53155453/cookoo_kicad.zi...

Not sure if this is the latest version.

They are in the repo:

Schematic - https://github.com/s-gv/cookoo/blob/master/schematic/whistle...

PCB - https://github.com/s-gv/cookoo/tree/master/pcb/gerber

Would harmonic product spectrum would work here? In my experience, it works very well for detecting the note frequency of guitar, piano etc.

What's the performance like?

I think college is a fun place to be until you figure out something productive to do. A lot of people feel that this is a "wrong" reason to do a PhD, but I actually agree with this view.

"The hopeless ones become college professors" - http://lemire.me/blog/archives/2015/02/25/hopeless-ones/

I agree. In fact, I think that the slowness of Python implementations is a feature. It forces developers to use standard libraries, which in turn makes the program more concise. This is certainly the case in MATLAB where vectorization is pretty much needed for non-trivial programs, and this leads to improved readability.

Collapsed by default HN (bookmarklet):

http://sagargv.blogspot.in/2014/06/flat-hacker-news.html

Does the ISA matter a lot these days? If we look at the mobile world, specifically Android, most programs are written in Java. So, as long as the compiler, the OS, and the JVM are ported to a new ISA, most apps will run happily.

Also, is binary ISA translation restricted by patents?

While I agree that teaching Python to non-EECS majors is a great idea, it's sad to see the decline of C/Scheme in university courses.

Much has been said on this topic. So, I'm just going to post two links that I think are interesting.

Joel Spolskey claims that Java isn't hard enough to separate good programmers from the bad: http://www.joelonsoftware.com/articles/ThePerilsofJavaSchool...

This article claims that competency of CS grads is going down: http://www.education.rec.ri.cmu.edu/roboticscurriculum/resea...

I've now implemented both these changes. The bookmarklet in the blog post (http://sagargv.blogspot.in/2014/06/flat-hacker-news.html) reflects this.

Thanks. I'll make these changes for the next version.

Joel Spolsky had written along similar lines and argued that it's important to know what is happening beneath abstractions.

http://www.joelonsoftware.com/articles/LeakyAbstractions.htm...

Yesterday, I saw Guy Kawasaki's talk on mistakes that entrepreneurs make.

https://www.youtube.com/watch?v=HHjgK6p4nrw

Modern GCs do not add much overhead when excess memory is available. When the app itself consumes a lot of memory and there is little room available, the GC gets stressed and eats too much CPU time. The chart in the link (taken from some paper) depicts this. The problem is the GC under low memory conditions, not Java.

Yes, the link is about JS. But there are relevant pieces.

Quote from the article: "If you want to process camera images on Android phones for real-time object recognition or content based Augmented Reality you probably heard about the Camera Preview Callback memory Issue. Each time your Java application gets a preview image from the system a new chunk of memory is allocated. When this memory chunk gets freed again by the Garbage Collector the system freezes for 100ms-200ms. This is especially bad if the system is under heavy load (I do object recognition on a phone – hooray it eats as much CPU power as possible). If you browse through Android’s 1.6 source code you realize that this is only because the wrapper (that protects us from the native stuff) allocates a new byte array each time a new frame is available. Build-in native code can, of course, avoid this issue."

An important aspect of mobile performance that this article doesn't really go into is memory. Its not just about CPU speed. Java performs quite close to C when excess memory is available, but performs poorly under low memory conditions. This is true of all GCed langs. The fact that iOS apps feel snappier is in no small part due to better memory management (ARC).

Source: Why mobile web apps are slow - http://sealedabstract.com/rants/why-mobile-web-apps-are-slow...

How does Microsoft benefit by open sourcing the C# compiler ? How will this drive users/developers towards Windows ?

Awesome ! I can't believe I hadn't thought of this before.