hogu

Are you using clone in a negative way? I don't think workflowy has a lock on outlines, One could say that workflowy is just an emacs org mode clone except on the web

well theoretically, as the more apps come in, more users will join, so there will be more wealth to be spread around. Though - I don't see myself paying for a social network ever.

honest question - does anyone use quantlib in production?

xlloop works for a bunch of languages, python, ruby, etc... But as far as i remember, xlloop is more of an RPC facility.

doing a scatter plot of 10k points in SVG is impractical - ok, so you could argue that you can't really see 10k points on the screen, that's fair, but if a user has 10k points, and they want to see them, you either have to figure out how to represent that with fewer points (collapsing a bunch of points into larger marks perhaps) or doing density estimation, or something else. To do it the naive way, SVG is impractical

I tried, if you ever nest svg it doesn't really work. If you don't do that, you might be ok.

just a small nitpick, you should be able to calculate portfolio variance using simple matrix operations instead of writing a double for loop.

something like.

temp = a* std_dev

var = np.dot(np.dot(temp.T, cor), temp)

backbone has very little magic in it - and the particular confusing aspect mentioned in this post has to do with ubinding events by calling .html, which has nothing to do with backbone, that's all jquery.

space bar doesn't seem to work for me (ubuntu, firefox and chrome)

If you have alot of data, and network IO is a big issue, you'll want to use something like hadoop (or disco) becuase they come with an integrated distributed file system and they preserve data locality.

If you don't have that much data, MR on redis is fine

I'm all in favor of better python interfaces for excel, but you need a better example, computing rolling time series statistics, and visualizing them? That's a job for pandas.

If you want excel as the front end (I understand why you would want that) you could use pandas to process the data, and use excel as the frontend, instead of writing all that code.

What I mean is that projects like coffeescript, and spine.js build classical inheritance patterns on top of JS and they work rather well.

I'm looking for someone to contrast either a classical inheritance system built on top of JS prototypes vs using JS prototypes in another way, OR just show me something cool you can do in JS prototypes, that you can't do with python or ruby classes. Contrasting js prototypes with classes in another language is fine for this exercise, I'm trying to understand conceptually why prototypal inheritance is good. Otherwise, I don't see how prototypal inheritance adds value over python/ruby inheritance schemes.

I also believe it's completely feasible and logical to critique language features, and still use them at the same time out of necessity. I still use prototypal inheritance, just through coffeescript classes

I don't think that's the issue, though I did come to JS from a python background, so that that for what it's worth.

For me the problem is that people tend to use prototypal inheritance to implement class inheritance patterns, but there are so many ways to do that, so whenever you read code, it takes a while to figure out what people are doing.

If there was a large gain to prototypal inheritance, I might be willing to accept it, but I havent' seen (does anyone have examples?) of really cool/useful things you can do with prototypes that you cannot do with class based inheritance? Because the increased flexibility leads to confusion without added benefit, I don't see the point.

Contrast that with dynamic typing, where I think there are huge benefits which offset the added cost.

also - from reading that article, it seems that JS's prototypal system has a large number of gotchas, and thats bad regardless of what kind of inheritance system your language implements.

not the person you're responding to, however I also made the change in the financial industry for a variety of reasons.

but the main one for me, was that python does non-math things much better than matlab. Since python is a general purpose language you can go from analysis to production application much faster, whereas with matlab it usually involved getting a software developer to rewrite it in java.

We used to take our python analysis code, wrap it up in a web app, and then use that to server risk information to traders, and it was quite easy to do so.

How would this be better than what we have now? Right now stocks already go to the highest bidder - if there is a seller willing to sell at that price. how would you run an auction if there are 40 firms trying to sell the same stock?

The ad market is well suited towards auctions because you have one seller for many buyers, but in finance you have a symmetric relationship between buyers and sellers.

Some have suggested that the problem was when the quotes were timestamped.

http://www.nanex.net/FlashCrash/FlashCrashAnalysis_NBBO.html

I don't really understand how you could abuse an exchange through quote stuffing - I've heard(and it seems reasonable to me) that they would use round robin queues to protect from exactly this sort of thing.

I think the problem is people come into zeromq expecting a high level library that handles all the details, zeromq does not do that, you need to handle reliability and disconnect behavior yourself. I agree that the default behavior in this case could be saner, but it's pretty easy to build reliable request reply in many different ways as illustrated in the guide, so I'm fine with it.

The benefit though, is that in zeromq you get to (and are forced to) choose exactly how your messaging patterns are reliable (or not)

how does one prevent someone from trading in their demurrage currency for something that holds its value when they do want to store value?

contribute to a project that many people use. create a project that fulfills many peoples needs.

If you do something that helps many people, people will notice.

reminds me of The Asylum film studios - they do the same thing, except for movies. I've been tricked into renting their movies instead of the real ones before, when I had forgotten the correct title.

http://en.wikipedia.org/wiki/The_Asylum

the python ws benchmark uses gevent with ws4py, it's also asynchronous - do you expect twisted to outperform gevent? why?

you can also get support for many open source projects on their respective irc channels, most of them are on irc.freenode.net

berkeley db is not similar, mongodb allows you to store json, and create indexes on many parts of the json, and query on those as well. with berkeley db you have to build that in yourself in the application, not in the database.

Using flask with websockets via gevent is pretty easy, I imagine this would also be true for other frameworks

Alot of us make visualizations during data exploration, where we don't have a message.

"With CoffeeScript, writing JavaScript becomes fun again. Code is cleaner and more verbose, leading to faster development and less bugs. Sure there’s opinions against it, but seems that many have changed their opinion? Just saying that you should try it. I’m not going back to vanilla JS. Debugging is not an issue when you use require.js. And plz don’t make those uncomprehensible magic one-liners."

How does require.js make coffeescript debugging easier?

There are many conservative banks that are starting to do enterprise projects in python. The primary reason why I would do that is the python ecosystem makes math and science easy to do

sincere question - Is your only data ingest mechanism by uploading gzipped csvs, or other files? it seems that if people really have big data, then by definition that approach won't work

spine clones models and sends that to callbacks, I've had strange problems with clones not updating properly, This is has to be user error, because I'm sure it would be a huge dealbreaker if this happened to everyone, but for me it was confusing enough and hard enough to diagnose that i gave up and went back to backbone.

or recruitment firms that want to remove your contact info from the resume before submitting it to their clients.