vivi.sh

Installing memusage on Ubuntu

Sun, 01 Mar 2020 00:00:00 +0000

For some annoying reason, Ubuntu does not package memusage in their libc.

Download a version of glibc that’s old enough to match your version of Ubuntu.
Compile and install into a destination that’s not /usr/local, I used PREFIX=~/glibc. Weird compiler errors probably means you need to try an older version.
Add $PREFIX/bin to your $PATH. In $PREFIX/bin/libmemusage you might have to change the memusageso=... line to where libmemusage.so lives ($PREFIX/lib/libmemusage.so) for the script to run successfully.

Speaking from experience: keep this thing far, far away from /usr or /usr/local or else you might brick your machine when you ldconfig and your entire system links into this glibc.

Maybe the real solution is to use Debian :-).

CS graduate school applications

Mon, 04 Feb 2019 00:00:00 +0000

I finished applying to graduate school programs last year! Here’s my recounting of the process.

Table of Contents

Advice that really helped me
Deadlines!
Getting Organized
GRE
Transcript(s)
Writing the SOP
Recommendation Letters
Submit & Wait!

Advice that really helped me

Jean Yang’s whole series on CS grad school
Philip Guo’s advice on graduate school applications and fellowships
- His memoir is a fun read too!
Justine Sherry’s advice
Mor Harchol-Balter’s advice

Deadlines!

Most CS graduate applications are due in mid-December.

HOWEVER, most fellowship applications are due 1-2 months before that! Finishing fellowship applications puts you in a good position to coast through your graduate school applications. Your ducks (rec. letters, SOP, misc. materials) will be properly lined up.

Getting Organized

I was casting a wide net, which means I had a lot of applications to submit. I found that a Trello Board was the most effective way of tracking my deadlines for each application.

I created four columns: overall application status and one for each recommendation letter writer. In each column, I put one card for each application I (or my recommender) had to complete.

I used labels to color-code the status and type of each card. Then, I could hover over each card and quickly label them by pressing 1 through 5.

I also added a link to the application in the “Description” field of the card and set the deadline on the card to be one day before the application’s real deadline.

GRE

I don’t have a lot to say about the GRE. From what I’ve heard, it’s not the most important part of your application, but schools don’t necessarily ignore it either. I prepared by taking the two tests that came with the registration fee, and studying these free Magoosh flashcards to build up my vocabulary.

Make sure to send scores to 4 schools of your choice at the testing center. Those 4 reports are free. I thought those 4 reports would still be free if I chose those schools later, but they actually cost $27 each if you don’t enter them at the testing center.

Transcript(s)

Some schools ask for a scanned copy of your official transcript. I would order the transcript (mailed to yourself) a few weeks before the deadline. Transcripts at some universities (cough UC Berkeley) take a few days to fulfill, so ordering early guarantees peace of mind.

Writing the SOP

In my experience, writing the SOP/NSF Personal History Statement was pretty difficult.

What helped me was spending the entire day enumerating all the research I did (a few paragraphs for each project), and using that to help me string everything together into a cohesive story. It feels much better once you have some words (even if they’re crap, you can always change the sentences and swap words out for fancier ones) to knead instead of staring at a blank page waiting for some godly narrative to hit you.

Here’s some questions that I found helpful answering:

What are specific part of [CS AREA] you interested in? Why?
What do you want to pursue in graduate school?
- I don’t think you need a detailed agenda, but more of a rough idea. I wrote that I was open to anything in the realm of systems and networks, but I supported this by explaining what I enjoyed about each research project and what they had in common.
Why do you want to go to graduate school?

For each project:

A few sentences explaining the problem.
A few sentences describing your contribution. Note anything interesting.
A sentence on it’s result (in publication, published, etc.)

Recommendation Letters

Most applications (except Hertz, which asks for 4) ask for 3 letters. My letters came from faculty who supervised my research over the past 2.5 years. I asked my recommenders at least a month before, but I also consistently reminded them as the deadline neared. They’re busy people–thank the stars for the Trello board!

If my recommender wanted more background information, I would give them a folder that contained by application materials (SOP, transcript, names of other recommenders) and some supplemental materials (description of research I did, teaching reviews).

Submit & Wait!

Weep at the state of your wallet, and wait for things to happen!

Some schools will interview starting in January, so it’s good to be aware of that while you’re on winter vacation. I have found that these interviews generally follow the same format: they ask you to explain your current research, and the discussion builds from there. They also give you the opportunity to ask about their program. One professor asked me for samples of my technical writing.

Making iTerm2 render faster

Sun, 20 Jan 2019 00:00:00 +0000

I really like using tmux and vim, but it was unbearably slow on iTerm2 (afaik, this is due to tmux. Running vim standalone is fine). Googling and profiling vim didn’t really help. I concluded that the Mac terminal emulator is just slow (?). Unfortunate.

I tried switching to Alacritty, which is very buttery, but I missed some of the features that iTerm2 has (e.g., the hotkey window).

In an attempt to make rendering faster, I turned off anti-aliasing (iTerm2 > Preferences > Profiles > Text > Uncheck Anti-Aliased). Anti-aliasing “smoothes” the jagged edges of curves. This makes your text look crisper. So, while tmux/vim performs well now, the terminal doesn’t look so good, but it’s fine for me. Trade-offs…

Aesthetic comparison:

Reading List

Tue, 01 Jan 2019 00:00:00 +0000

Graduate School Advice

The N=1 guide to grad school (and hopefully, knowledge work)

To Read

I migrated laptops and everything broke.

Wed, 21 Nov 2018 00:00:00 +0000

A few weeks ago, my laptop’s screen gave out. I switched to a new laptop, and used Apple’s handy-dandy migration assistant, which worked well for everything except my development environment.

The first sign of trouble was when I tried to run bundle and got

/usr/local/bin/bundle: /usr/local/opt/ruby/bin/ruby: bad interpreter: No such
file or directory 

…what? I tried reinstalling Homebrew’s ruby, which didn’t work.

When I ran brew upgrade, many packages could not be built because it could not find dependencies in /usr/local/opt (double what?). I started individually re-installing packages (via brew unlink and brew link, but realized that most of the errors laid in a bunch of files in /usr/local/share. Luckily, anything in usr/local is not critical to the OS, so you can remove files (at the risk of reinstalling missing dependencies, which I was doing anyways).

I ended up doing this to fix my troubles:

Empty /usr/local/share
Run brew update && brew upgrade
Run brew list | xargs brew reinstall
For good measure, run brew doctor and fix what it complains about.
I also started using rbenv. Even though I never use ruby, it’s nice (I can run jekyll without prepending bundle!)

Live word count in vim airline

Mon, 15 Oct 2018 00:00:00 +0000

This was a result of using vim to write my essays. I started writing them in notes (vim-notes plugin) files and wanted vim-airline to display a live word count.

The Easy Way

As of this version of vim-airline’s wordcount plugin.

In your vimrc, add:

" Enable wordcount
let g:airline#extensions#wordcount#enabled = 1
" Add notes to filetypes
let g:airline#extensions#wordcount#filetypes = '\vnotes|help|markdown|rst|org|text|asciidoc|tex|mail'

The Complicated Way

Note: When I came up with this, I was really frustrated because I could not figure out `The Easy Way’ – the wordcount plugin went through a few re-writes that left the documented format of expressing filetypes outdated. So I decided to figure out how to write it by myself. Of course, I would figure out the easy way after I finished documenting the complicated way. Go Vivian.

You can get word count by typing g Ctrl+g in normal mode, or in visual mode (which will tell you how many words are selected).

First, I define a function that grabs the word count using the above command. First, it saves the position of the cursor. Then, it parses v:statusmsg by looking at whether you’re in Visual mode or not.

function! WordCount()
    let position = getpos(".")
    exe ":silent normal g\<c-g>"
    let stat = v:statusmsg
    let s:word_count = 0
    if stat != '--No lines in buffer--'
        if mode() == "V"
            let s:word_count = str2nr(split(stat)[5])
        else
            let s:word_count = str2nr(split(stat)[11])
        endif
    endif
    call setpos('.', position)
    return s:word_count
endfunction

This is how I made it show up in airline for files of the type note. Note that vim-airline automatically handles this for some set of default filetypes (see The Easy Way).

function! AirlineWC(...)
    if &filetype == 'notes'
        let w:airline_section_b = '%{WordCount()} words'
    endif
endfunction
call airline#add_statusline_func('AirlineWC')

A collection of tips

Mon, 26 Dec 2016 00:00:00 +0000

I graduated! I decided to leave some updates/comments in text like this.

I’ve been at UC Berkeley for ~3 semesters now, and it’s been a blast! Here’s a fun list of tips I’ve compiled for this semester (Fall ‘16).

I took classes for a total of 6 semesters. Currently, I am working as a research assistant and applying to graduate school. Here are tips as of Fall ‘18!

General

Don’t kill yourself with techs.

$$\text{your happiness} \propto \frac{1}{\text{classes you're taking}}$$

Unless you’re crazy good at classes. I took 4 CS classes this semester (61C/70/168/188), and while I learned a lot, I didn’t do the best I could in each class. Additionally, I didn’t get to spend a lot of time on other interesting things (teaching, research). It’s really a matter of your own happiness and what you’re optimizing for.

There is some serious FOMO when it comes to taking classes, especially at the upper-div level. Take the classes that are interesting.

Figure out your passion.

Maybe I’m a contrarian, but… AI/ML is a really sexy field right now, and everyone wants to get into it. Does that mean you should automatically apply for every AI lab on this campus? No, you shouldn’t. Instead, ask yourself, are you genuinely interested in AI/like math or are you interested because it’s hot shit right now and all the cool kids are talking about it? Realize that there are so many other fields in CS that are neat and worthy of your time. Don’t come in with a narrowed list without exploring all the options first.

I had no clue what I was interested in my first year. I just said “AI” to anyone that asked since it seemed like everyone was talking about it. I’m ended up becoming interested in another sub-field.

Reward yourself and go outside!

There’s a lot of cool things to do in Berkeley that don’t include school or studying. Here’s a few suggestions:

Big C hike
Go up the Campanile (free for students!)
Rose gardens
Tilden Park
Movie theaters
- I ended up watching more movies in college than high school
Yoga @ RSF (free for students!)
- They provide mats, which is good for your first couple times, though I think it’s worth it to invest in your own mat.
Eating poutine after finals lol

Let me add some more:

Explore beyond the bubble that is UC Berkeley’s campus (and anything within a 0.5mi radius…).

San Pablo Ave is filled with great food: Middle Eastern Market has the best kebabs, ever. Baklava too. Super Super Restaurant has excellent pho.

Walk a few blocks west, cross the bridge, and you’ll reach the marina. It’s BEAUTIFUL.

Go north on Shattuck and you’ll hit:

Cheeseboard, Gregoire, Saul’s

(like 2 miles north) Indian Rock. Great view.

BART over to SF and just walk around. Bask in the consumerism.

BART to Oakland.

Walk around Lake Merritt. Look at the birds!

Go to Chinatown and eat your heart out.

Every Friday night, many food trucks gather around OMCA. The museum is also open for extended hours. Students get a discount on museum admission!

The Bay Street Mall in Emeryville has a Dippin Dots vending machine. Just sayin’.

Join a club. It’ll help you meet people outside of your major!

EECS / CS Specific:

Getting that sweet summer internship shouldn’t be your life goal.

Hear me out here - especially if you’re a freshman. I find that people come in rushing to find an internship, before even checking out other things you can do over the summer - research, teach, take classes, chill, etc.

I still agree with this. Chilling is important.

Classes I like:

CS 168 - If you have the opportunity to take this (it’s usually offered in the Fall), I highly urge you to do so! Scott Shenker is one of the most caring and inspiring professors I’ve met. Also, don’t you want to learn more about one of the biggest CS innovations (the Internet)?

More classes!

CS 162 - How do operating systems work? How does it all add up? Really makes what you learn in 61C make sense. Also, learn how to write lots of C.

CS 262a - Take this if you like 162. The class is structured differently – you’re reading a bunch of papers every week instead of completing programming homeworks/projects. But, wow, these papers are really valuable. Your term project is usually a research project related to OS/Systems.