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3
Jun

Due to my job, family, writing ‘Learning Highcharts (2nd Ed)’ and many other commitments. I won’t be able to answer all the questions.

If you require time consuming help, I am willing to provide a consultation service.

Many thanks

Joe (Contact me)

Read more

1
Oct

Creating Bash 4.3.27 source package

Due to the severity of shellshock bug, I have to patch some of the internal legacy systems, like FreeBSD 8.0 which there are no more updates available. The only way I can update is to download the source from GNU site and build from that. However, the main source package is only available at version 4.3.0 at the time of writing. To remove the shellshock bug, it needs at least version 4.3.25. Although all the patches are located in the bash-4.3-patches directory, not of all them were created by pointing to “../bash-4.3″ directory, some with different names.

So here it is, I have created this bash source package 4.3.27 with all these patches. I built it on FreeBSD and it passed the env test.

22
Sep

Highcharts extension for Sencha ExtJs now includes Highmaps support

screen
The new release now includes Highmaps support. A new online demo is setup and the demo code is included in the new release under the directory, highmaps_demo.extjs4. Read more »

14
Sep

Highcharts extension for ExtJs 4/5 is here now

screen Highcharts Extension 3.1.0 now supports ExtJs 5. It includes couple updates:

- All demos now refer to ExtJs CDN rather than from my demo site

- Added support for Solid Gauge series

Apart from removing deprecated methods in ExtJs, all the existing code should work directly with this extension & ExtJs 5. There are known issues using with sencha command which I still need more user feedbacks and time to resolve this. Hopefully, I will find some time to finalise my Highmaps extension for ExtJs.

8
May

Highcharts 4 extension for ExtJs is here

Highcharts 4 extension for ExtJs

A new version of Highcharts extension for ExtJs 4 is released. This extension (3.0.1) is a major release which includes following updates:

  • supports Highcharts 4 including the long waited 3D charts and heatmap (in beta)
  • added missing Pyramid series
  • beta support for Highmaps

The documentation has also been updated. Check out the demos on 3D charts and the license for usage. The demos for Highmaps and heatmap will be coming soon which will be implemented in separate web application (using Sencha Architect).

24
Feb

A new look for my demo page

After a couple attempts of redesigning my homepage, I decided to fall back to simplistic approach. A simple grids base demo using jQuery thumbnail and lightbox to popup each demo.

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8
Feb

Web based Gapminder

If you haven’t heard of Gapminder, then watch this very charismatic presentation from Ted talk by Prof. Hans Rosling. Basically, Gapminder is a Flash application which presents the world of statistics and demonstrates how it has evolved over centuries. It has been in my long overdue tasks list to implement a web based Gapminder using my Highcharts extension for ExtJs. So far it took me few hours a week over couple months to come up with this prototype. The challenge is that simultaneously updating and animating nearly 300 data points (with color shading) in a fraction of a second is quite CPU intensive. At least, it is possible now in HTML5.

The following is a short video demo of the prototype. It is running under my Mac Mini (Quad core 2.3GHz i7 – 4G RAM).

However, there are still plenty to implement. Online demo and code on github will be available soon

1
Dec

Implementing Stock Picking Wheel in Highcharts

Investor Wheel in Highcharts

This is the work that I have done a while ago but I didn’t have time to write up. About 6 months ago, I saw an impressive chart, Stock Picking Wheel, which represents a list of FTSE 100 stocks and their performance summarised in a donut chart. So I gave myself a challenge to see whether it is possible to implement in Highcharts and here it is. Read more »

17
Nov

Extract a list of symbols from stock exchange indices

As far as I know there is no free web service that can produce a single page of stock symbols from a stock exchange. Moreover, for webpages that produce stock symbols, all of them only output with pagination. However, the easiest webpage to extract the symbols list is the Yahoo finance. This article shows how to extract a full list of symbols with a few repeated commands.

For Yahoo Finance, each page list approximately 50 symbols and it takes 3 calls to get all the symbols of FTSE 100 stock exchange. Here are the commands:

# Return the first 49 symbols
curl -s "http://uk.finance.yahoo.com/q/cp?s=%5EFTSE" | grep -o '>[A-Z]*\.L</a>' | sed -n "s/>\(.*\)<\/a>/\1/p"
# Return the next 50 symbols
curl -s "http://uk.finance.yahoo.com/q/cp?s=%5EFTSE&c=1" | grep -o '>[A-Z]*\.L</a>' | sed -n "s/>\(.*\)<\/a>/\1/p"
# Return the final symbol (last page)
curl -s "http://uk.finance.yahoo.com/q/cp?s=%5EFTSE&c=2" | grep -o '>[A-Z]*\.L</a>' | sed -n "s/>\(.*\)<\/a>/\1/p"

For Dow Jones Industrial Average, it returns 30 symbols

curl -s "http://finance.yahoo.com/q/cp?s=%5EDJI" | grep -o 'q?s=[A-Z]*">[A-Z]*' | sed -n 's/.*=.*">\([A-Z]*\)<\/a>/\1/p'

For Nasdaq Composite, it is the same as above except changing the cp query to s=%5IXIC and repeat for many pages with parameter c. Alternatively, you can use this link to download the whole list.

11
Oct

Installing new kernel within Linux kickstart

I have to build a Ubuntu installer ISO using the kickstart utility but I need the installer to install a particular version of kernel. Here is the link for a quick guide on setting up Ubuntu kickstart. First, I added the following line into %packages section in the installer build script to install the target kernel package, ks.cfg: Read more »

12
Jun

[Updated] ExtJs 4.2: Changing column’s editor dynamically in ExtJS RowEditor

ExtJs 4 Row EditorA while ago I have written a blog on how to change the field type inside a row editor dynamically with ExtJs 3. Since then I received a number of requests for the same example in ExtJs 4. It has been way overdue, so here it is.

An online demo is available in joekuan.org and the source code can found in github.

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