Develop Reference

Replacing an equation and embedding a math function plotter?

I am actually searching for a javascript / jquery library where I can pass a function equation, such as sin(x^2), and it plots the graph. Example link:
http://www.greatgraphing.me/?plot=sin(x^2)
Furthermore, I would like to scan my website for function equations and replace them with this function graph embed. It should have navigation features (scrolling, dragging the stage etc).
Over the last 4 hours I have searched the net without satisfactory result. Even the popular plot.ly, fooplot.com and jsxgraph do not offer this kind of features. The only thing that comes close to what I need is www.graph.tk. You can pass 1 equation by URL but it has no embed feature (widget or alike).
Wolframalpha offers a widget but it seems to be just an embed without the option to pass the equation.
Update: Found out that desmos.com offers an embed feature, if you purchase one of their API keys. Price is not stated.
I also considered using Google's geometry calculator but there seems to be no embed features.
Before starting to build such a "graph embed" myself, I would like to ask if such a project exists already. Maybe it is hidden in some github repo and I just can't find it.
Thank you.
PS: If the question is too offtopic (saw the first close flag), even though it is related to js/jquery, where should I ask it? On Superuser? Please advice me. I am sure this is an important question for many math developers.

All right, I took the time to write a first prototype based on jquery, math.js and easeljs (about 300 KB with v0.0.1):
graphobed
Demo: http://www.matheretter.de/tools/graphobed.html
Source: http://www.matheretter.de/tools/graphobed.html or here: https://raw.githubusercontent.com/echteinfachtv/graphobed/master/graphobed.js
Github repo: https://github.com/echteinfachtv/graphobed
Disclaimer: The code is a bit messy but worked in my tests. You just have to embed the js file, the script runs over all elements on your site and parses only if an enclosed equation has been found, the characters for enclosing are: *# x^2*sin(x) #*
I also added the possibility to change the graph later on by simply providing an input field. So after the embed you can change the graph as you wish:
Enjoy and improve the source code if you like :)

Javascript library to manage translation forms

Is anybody aware of any javascript tool (compatible with jQuery, tinymce or any other clientside library) able to manage the following requirements?
I need to show translation forms in which every field (either input or textarea) could contain some segment variables or code sections (mostly HTML).
For example:
"Hello {{firstname}}, this is your personal page."
or
"You improved your personal score of <strong>{{n}} points</strong>."
Of course I obtain these segments from a template parser and I need to show them to a set of translators that will perform localization towards many languages. I know that in many cases I can (and should!) avoid variables and code inside translation segments, but in many other cases I really can't.
The problem is: I would like to manage coherence about variables and code directly on the browser (I trust my translators but a bit more of UI/UX help is always a good thing!).
A nice approach could be providing the set of variables and code tags, ready to be inserted by means of a single click (in order to avoid mispelled variables or incorrect code syntax) and a bit of pre-submit validation to be sure everything was inserted.
I've seen this approach in other websites, such as Facebook or Freelancer.com (who have the power and the ability to reimplement the whole thing from scratch!).
Do you know about any almost-ready tool/library for this purpose?
Thank you all in advance for any suggestion.

If you are asking for a library to translate text - here is Google Translate API: https://developers.google.com/translate/?csw=1
If you are asking for a library which can take user input, perform validation, and insert into the DOM - then Jquery has everything you need.
If you are asking for something else, let me know and I'll edit my question.

How to implement different languages on html page

I am just a newcomer developing an app with html/css/js via phonegap. I've been searching info on how to make my app be displayed in different languages and Google doesn't understand me.
So the idea is to have a button on index.html that let the user choose the language in which the app will be displayed, in this case Spanish/English, nothing strange like arabic blablabla....
So I guess that the solution must be related to transform all the text that I load in html to variables and then depending on the language selected display the correct one. I have no idea how to make this, and Im not able to find examples. So that's what Im asking for... if someone could give some code snipet to see how html variables works and how should I save user language selection...
Appreciated guys!

This can be done by internationalization (such as i18N). To do this you need separate file for each language and put all your text in it. Search Google for internationalization.
Otherwise you can look into embeding Google Translate.

This depends on the complexity of language-dependencies in the application. If you have just a handful of short texts in a strongly graphic application, you can just store the texts in JavaScript variables or, better, in properties of an object, with one object per language.
But if you expect to encounter deeper language-dependencies as well (e.g., displaying dynamically computed decimal numbers, which should be e.g. 1.5 in English and 1,5 in Spanish), then it’s probably better to use a library like Globalize.js (described in some detail in my book Going Global with JavaScript and Globalize.js). That way you could use a unified approach, writing e.g. a string using Globalize.localize('greeting') and a number using Globalize.format(x, 'n1') and a date using Globalize.format(date, 'MMM d').

Python 3, Web-scraping, and Javascript [Oh My]

I have come to the point of entering the melee on web-scraping webpages using Javascript, with Python3. I am well aware that my boot may be making contact with a dead horse, but I feel like drawing my six-shooter anyway. It's a spaghetti western; be my gray hat?
::Backstory::
I am using Python 3.2.3.
I am interested in gathering historical stock//etf//mutual_fund price data for YTD, 1-yr, 3-yr, 5-yr 10-yr... and/or similar timeframes for a user-defined stock, etf, or mutual fund. I set my sites on Morningstar.com, as they tend to provide as much data as possible without necessarily requiring a log-in; other folks such as finance.google.com &c tend to be inconsistent in what data they provide regarding stocks vs etfs vs mutual funds.
The trade-off in using Morningstar for this historical data, or "Trailing Total Returns" as they call it, is that for producing this data they use Javascript.
Here are some example links from Morningstar:
A Mutual Fund;
An ETF;
A Stock.
I am interested in the "Trailing Returns" portion, top row or so of numbers in the Javascript-produced chart.
::Attempted So Far::
I've confirmed that wget doesn't play with Javascript; even downloading all of the associated files [css, .js, &c] hasn't allowed me to locally render the javascript in browser or in script. Research here on StackOverflow confirmed this. Am willing to be corrected here.
My research informed me that Mechanize doesn't exist for Python3. I tried anyway, and turned into Policeman Javert crying out "I knew it!" at the error message "module does not exist".
::I've Heard Of...::
->Selenium. However, my understanding is that this requires Thy Favorite Browser to actually open up a webpage, navigate around, and then not close because there's no "close this tab//window" command//option for Selenium. What if I//my_user want to get historical data for many etfs, stocks, and/or mutual funds? That's a lot of tabs//windows opening up in a browser which was not necessarily desired to be opened.
->httplib2. I think this is nice, but I'm doubtful if it will play with Javascript. Does it, for example using the .cache and get options?
import httplib2
conn = httplib2.Http(".cache")
page = conn.request(u"http://the_url","GET")
->Windmill. See 'Selenium'. I am, however, off-key enough to sing 'Man of La Mancha'.
->Google's webscraping code. Would an attempt at downloading a Javascript-laden page result in ... positive results?
I've read chatter about having to "emulating a browser without a browser". Sounds like Mechanize, but not for Python3 as I currently understand.
::My Question::
Any suggestions, pointers, solutions, or "look over here" directions?
Many thanks,
Miles, Dusty Desert Villager.

When a page loads data via javascript, it has to make requests to the server to get that data via the XMLHttpRequest function (XHR). You can see what requests they are making, and then make them yourself, using wget!
To find out which requests they are making, use the Web Inspector (Chrome and Safari) or Firebug (Firefox). Here's how to do it in Chrome:
wrench/tools/developer tools/Network (tab at the top of the tools)/XHR filter at the bottom.
Here's an example request they make in javascript
If you look closely at the XHR request url, you notice that all trailing returns have the same format:
http://performance.morningstar.com/Performance/cef/trailing-total-returns.action?t=
You just need to specify t. For example:
http://performance.morningstar.com/Performance/cef/trailing-total-returns.action?t=VAW
http://performance.morningstar.com/Performance/cef/trailing-total-returns.action?t=INTC
http://performance.morningstar.com/Performance/cef/trailing-total-returns.action?t=VHCOX
Now you can wget those URIs and parse out the data directly.

What is the best way to filter spam with JavaScript?

I have recently been inspired to write spam filters in JavaScript, Greasemonkey-style, for several websites I use that are prone to spam (especially in comments). When considering my options about how to go about this, I realize I have several options, each with pros/cons. My goal for this question is to expand on this list I have created, and hopefully determine the best way of client-side spam filtering with JavaScript.
As for what makes a spam filter the "best", I would say these are the criteria:
Most accurate
Least vulnerable to attacks
Fastest
Most transparent
Also, please note that I am trying to filter content that already exists on websites that aren't mine, using Greasemonkey Userscripts. In other words, I can't prevent spam; I can only filter it.
Here is my attempt, so far, to compile a list of the various methods along with their shortcomings and benefits:
Rule-based filters:
What it does: "Grades" a message by assigning a point value to different criteria (i.e. all uppercase, all non-alphanumeric, etc.) Depending on the score, the message is discarded or kept.
Benefits:
Easy to implement
Mostly transparent
Shortcomings:
Transparent- it's usually easy to reverse engineer the code to discover the rules, and thereby craft messages which won't be picked up
Hard to balance point values (false positives)
Can be slow; multiple rules have to be executed on each message, a lot of times using regular expressions
In a client-side environment, server interaction or user interaction is required to update the rules
Bayesian filtering:
What it does: Analyzes word frequency (or trigram frequency) and compares it against the data it has been trained with.
Benefits:
No need to craft rules
Fast (relatively)
Tougher to reverse engineer
Shortcomings:
Requires training to be effective
Trained data must still be accessible to JavaScript; usually in the form of human-readable JSON, XML, or flat file
Data set can get pretty large
Poorly designed filters are easy to confuse with a good helping of common words to lower the spamacity rating
Words that haven't been seen before can't be accurately classified; sometimes resulting in incorrect classification of entire message
In a client-side environment, server interaction or user interaction is required to update the rules
Bayesian filtering- server-side:
What it does: Applies Bayesian filtering server side by submitting each message to a remote server for analysis.
Benefits:
All the benefits of regular Bayesian filtering
Training data is not revealed to users/reverse engineers
Shortcomings:
Heavy traffic
Still vulnerable to uncommon words
Still vulnerable to adding common words to decrease spamacity
The service itself may be abused
To train the classifier, it may be desirable to allow users to submit spam samples for training. Attackers may abuse this service
Blacklisting:
What it does: Applies a set of criteria to a message or some attribute of it. If one or more (or a specific number of) criteria match, the message is rejected. A lot like rule-based filtering, so see its description for details.
CAPTCHAs, and the like:
Not feasible for this type of application. I am trying to apply these methods to sites that already exist. Greasemonkey will be used to do this; I can't start requiring CAPTCHAs in places that they weren't before someone installed my script.
Can anyone help me fill in the blanks? Thank you,

There is no "best" way, especially for all users or all situations.
Keep it simple:
Have the GM script initially hide all comments that contain links and maybe universally bad words (F*ck, Presbyterian, etc.). ;)
Then the script contacts your server and lets the server judge each comment by X criteria (more on that, below).
Show or hide comments based on the server response. In the event of a timeout, show or reveal based on a user preference setting ("What to do when the filter server is down? (show/hide comments with links) ).
That's it for the GM script; the rest is handled by the server.
As for the actual server/filtering criteria...
Most important is do not dare to assume that you can guess what a user will want filtered! This will vary wildly from person to person, or even mood to mood.
Setup the server to use a combination of bad words, bad link destinations (.ru and .cn domains, for example) and public spam-filtering services.
The most important thing is to offer users some way to choose and ideally adjust what is applied, for them.