写一个getPath函数，从document里找到父js的路径，拼到Worker的名字上。对heatcanvas.js这个文件来说就是：

因此现在HeatCanvas已经解决了这个路径问题，现在这个库应该更好用了。当然如果你改了我的文件名我就无话可说了。

时隔半年日日沉浸在clojure世界里的时候，多亏了github上Daniel Azuma的提示，现在HeatCanvas通过Image Data数组来绘制图像。过去由于不太熟悉Canvas API，我用的是fillRect来填充1像素大小的区域，模拟像素的渲染。但是这种方式导致浏览器渲染的效率非常低。

ImageDataArray允许用户开辟一个固定大小的buffer，并设置每一像素的像素值，然后一次性地渲染到canvas上。详情可以参考这里：Pixel manipulation with canvas

这次性能的提升基本没有影响API，唯一的区别是如果原先自定义了value-color的映射函数的话，现在不再接受hsl的css字符串了，新的API需要你返回一个四个元素的数组，分别代表h, s, l, a，值域[0-1]。

感谢关注HeatCanvas的朋友。

Mootools本身也沉寂了很久，这个项目恐怕也要思考自己未来的发展方向了。今年9月Mootools迈进了1.4，API上有一些变化。现在的下载页也能看到with/without backward compatibility的版本分开下载。为了用上Roar，我尝试了这两个版本发现都不能使用。最后downgrade到1.2可以确定Roar本身在当时是没有什么问题。

这么多年对mootools痴心不改，所以顺手维护了一下Roar，现在可以在1.4 without compatibility的发布下运行了。主要是几个小修改，大多是一些多年deprecated函数被正式删除：

• Type常量，原先的String.type，Object.type现在统一到一个Type对象下，变成Type.isString和Type.isObject
• $empty 常量被删除了，现在直接用function()或Function.from()代替
• $pick 方法被Array.pick取代，参数现在也必须接受数组类型了
• $merge 方法被Object.merge取代
• $type 被typeOf取代
• 函数对象的create方法被删除了，现在可以用函数对象的bind方法替代
• Browser.Engine 被删除了，需要用其他Browser的API替代

修改后的Roar，放在这个gist里，测试过可以在firefox和chromium上健康使用。IE没有做测试。这个08年的库，眼看四年过去了，用起来依然不错。

作为mootools的铁杆，我还是会一直专一地坚守下去的。（于是，我也已经变成了多年前那些我眼中为旧事物顽抗到底的老家伙了）

However, different from clojure’s interoperability with Java, ClojureScript has its own characteristics when you are interoperating with JavaScript and JavaScript based libraries.

Clojure types are not fully compatible with JavaScript types
In ClojureScript, you can never treat a Clojure map as a JavaScript object although they have similar characteristics. You have to do some conversion before passing a clojure map to javascript functions. Matthew Gilliard made a sample of such conversion.

JavaScript package is not Clojure namespace
This could be a common mistake for ClojureScript newbie. Actually, JavaScript doesn’t have concept of “Package” or “Namespace”. Many JavaScript libraries(dojo, Google Closure) made enhancement on this. ClojureScript also takes advantage of this mechanism. So before you start to coding with closure, you may browse closure library API document, and find a module called goog.net which includes lots of types. Then you write this:

But compiler shows you “ERROR: JSC_MISSING_PROVIDE_ERROR. required “goog.net” namespace never
provided at … “. This is not a PATH issue. The root cause is that closure module has a lower granularity than Clojure ones. Types are often contained in their own modules. You can find closure source code in clojurescript/closure/library/closure. Modules are declare with goog.provide function. Thus, you should require this name instead of the logical module name.

In addition, ClojureScript does not support ‘use’.

Just use full name for JavaScript class
For functions contains in some module, you can refer it with the clojure way:

But for classes, just use the full name and ignore the module alias.

These are basic tips before you start using Closure with ClojureScript. Leveraging on Google’s closure library, you can create cross-browser JavaScript application with Clojure easily.

HeatCanvas-Leaflet extension enables heat map on Leaflet. You can create heat map layer and add it to Leatlet map:

You can find live demo on:
http://sunng87.github.com/heatcanvas/leaflet.html
Mobile browser is also supported. (Tested on Firefox Android and default Android browser)

Find more about HeatCanvas on github page.

Leaflet is still buggy for extension. There is a latlng-pixel coordinate conversion issue in low zoom level, affects this demo. Hope it could be fixed soon.

安装
npm install ngeohash

使用
var geohash = require(‘ngeohash’);
sys.puts(geohash.encode(32.1717, 118.2342));

详细
访问github的相关页面：https://github.com/sunng87/node-geohash

感谢@lbt05姐的无私贡献，现在HeatCanvas又增加了百度地图API支持。你可以在你的百度地图中使用heat map了。详情可以参考@lbt05姐撰写的文档，而这里是一个简单的live demo。此外，@lbt05姐还贡献了GoogleMap扩展的patch，帮助我解决了地图拖动后Canvas无法覆盖viewport的bug。再次感谢@lbt05姐。

百度地图支持已经汇入主干，可以在github找到它。

Gefr新增 Jetty WSGI Bridge

昨天为gefr新增了Jetty服务器的支持，这样你可以将自己的Python WSGI程序运行在成熟的Jetty服务器上。性能是大家关心的因素，下面是在我的本机（32位CentOS，双核2.8GHz，4G内存）上一个粗略的测试结果：

100并发，20000请求：

Server Software: gefr-jetty/0.3dev
Server Hostname: localhost
Server Port: 8088

Document Path: /
Document Length: 19 bytes

Concurrency Level: 100
Time taken for tests: 3.120827 seconds
Complete requests: 20000
Failed requests: 0
Write errors: 0
Total transferred: 2584515 bytes
HTML transferred: 380665 bytes
Requests per second: 6408.56 [#/sec] (mean)
Time per request: 15.604 [ms] (mean)
Time per request: 0.156 [ms] (mean, across all concurrent requests)
Transfer rate: 808.44 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 4 114.1 0 3000
Processing: 0 7 18.5 5 1776
Waiting: 0 6 18.5 4 1776
Total: 0 12 115.8 6 3015

Percentage of the requests served within a certain time (ms)
50% 6
66% 7
75% 8
80% 8
90% 10
95% 13
98% 70
99% 74
100% 3015 (longest request)

如果打开KeepAlive，吞吐量可以达到10000以上：

Server Software: gefr-jetty/0.3dev
Server Hostname: localhost
Server Port: 8088

Document Path: /
Document Length: 19 bytes

Concurrency Level: 100
Time taken for tests: 1.749189 seconds
Complete requests: 20000
Failed requests: 0
Write errors: 0
Keep-Alive requests: 20000
Total transferred: 3062142 bytes
HTML transferred: 380266 bytes
Requests per second: 11433.87 [#/sec] (mean)
Time per request: 8.746 [ms] (mean)
Time per request: 0.087 [ms] (mean, across all concurrent requests)
Transfer rate: 1709.36 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.8 0 23
Processing: 0 8 8.0 6 85
Waiting: 0 8 8.0 6 85
Total: 0 8 8.1 6 85

Percentage of the requests served within a certain time (ms)
50% 6
66% 7
75% 8
80% 9
90% 11
95% 20
98% 41
99% 43
100% 85 (longest request)

你可以根据gefr的文档安装它。

As the screenshot shows, now you can embed HeatCanavs in your OpenLayers application, as well as OpenSteetMap.

Three steps to create such kind of map:

1. Create HeatCanvas layer:

2. Feed some data on layer:

3. Add layer to map:

The live demo is hosted on github:
http://sunng87.github.com/heatcanvas/openstreetmap.html

HeatCanavs is a heat map implementation on HTML5 canvas and WebWorker API.

HeatCanvas is based on the prototype I wrote 15 months ago. I just rewrite the whole with WebWorker API to keep user away from UI frozen and annoying slow-script warning. HeatCanvas is implemented as pixel based, so the image quality is great.

The API is rather simple. There are only three steps to create a basic heat map.

1. Create the heat map object:

2. Add some data to heat map:

3. Render it:

In contrast to the base API, HeatCanvas also supports flexible options to customize the rendering. Even custom colour scheme is allowed. You can refer to the doc for detail.

And for your convenience, we have a GoogleMap plugin, HeatCanvasOverlayView, that wraps HeatCanvas. You can use it in your GoogleMap application.

For live demos, you can find at:
http://sunng87.github.com/heatcanvas/

As always, the project is hosted on github:
https://github.com/sunng87/heatcanvas .

The three javascript files are only necessary in your application, thus, please ignore the htmls in your deployment. Any feedback is welcomed and also please kindly let me know your application using this API.

coffeescript的几个特点也属于博采众长：

• 类似python的，以缩进取代代码块
• 类似ruby/perl，方法调用括号可选
• 类似ruby，无须return
• 正常的类声明语法

在nodejs的环境里可以通过npm安装coffer-script，利用它的命令行程序，可以把coffeescript编译成javascript。不过最给力的是可以在网页里通过引入coffee-script.js来直接执行（其实也是编译一下）coffeescript。

于是我顺手重写了一下首页的js，改写成coffeescript。因为少打很多() {}，手可以控制在键盘中心的，敲字的效率大大提高。用空你也可以尝试一下。