Sandeep's Tech and Design Blog

Color Brewer is a great website for experimenting and learning about different considerations for designing color schemes for maps. This information is useful for other visualizations like tables, areas charts also. The three type of data sets you can work with are Sequential ordered data like population density Diverging, e.g population by age band Qualitative which means discrete values like Ethinicity Color Brewer

Below is a great data story telling visualization. It was the winner of the Kantar Information is Beautiful award Data Storytelling using a Chord Diagram

We can use a variable width bar chart to visualize two qualitative variables. This is a type of a Mosaic Plot

Instead of a single donut chart or a circular status meter gauge you can use a radial bar chart or pie gauge to display your chart in a more compact form Radial Bar Chart

A well designed color scale can help the user make better sense of their data. chroma.js helps with generating color scales that do a better transition for colors Mastering Multi-hued Color Scales with Chroma.js

I saw this wonderful visualization in the Time Magazine that breakouts how $10,000 in income taxes is spent by the US government. This visualization is very easy to understand and does a great job of breaking out hierarchies from an Agency such as the US military down to a more specific line item such as Nuclear Weapons. Also note the font weighting based on the number value.

A Cartogram is a geometric distortion of a thematic map using a variable such as population See an animation of cartogram as it transitions from a map to a population cartogram of the world here . Cartogram Wikipedia

We are typically used to seeing satellite imagery with a top down view. Planet.com's satellite now image the earth daily and are also taking oblique views. See these amazing photos in this blog Earths Wonders with oblique views

Linux has come a long way in the last 20 years. Surprisingly Linux usage at home seems to be shrinking, but growing in the enterprise. I think 5 years back the only serious alternative to Windows at home was Linux. But with the popularity of Apples iMac and Macbook, the usage of Linux is declining at home. See the following infographic on how Linux and the Internet  has changed over the last 20 years

A Math Graphing Startup, that should help with big data analysis. http://techcrunch.com/2011/06/24/desmos-graphing-calculator/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Techcrunch+%28TechCrunch%29

If you create a table with an XMLTYPE column create table test (name varchar2(60), xml_col xmltype) ; You get the following error message Error starting at line 22 in command: create table test (name varchar2(60), xml_col xmltype)  Error at Command Line:22 Column:0 Error report: SQL Error: ORA-43853: SECUREFILE lobs cannot be used in non-ASSM tablespace "TBS_3" To work around this problem all you need to do is define the Column storage for the XMLTYPE column to b a clob. SQL> create table test (name varchar2(60), xml_col xmltype not null) xmltype column xml_col store as clob SQL> insert into test values ('abc', xmltype(' World ')); SQL> select name, extractvalue(xml_col, '/hello') value from test3 Name        Value ----------------- Hello       World

When I design and implement a new API, I always like to make the API easy to use. I was implementing a set of classes for usage in a Tree and a TreeTable. The only thing I wanted the user to implement is a class that defines the Node Data. For the Tree Table case I also needed information on getting the column count and whether the column was editable. My first implementation was to make it part of an interface public interface ColumnData { public void setData(int index, Object value); public Object getData(int index); public String[] getColumn(int index); public boolean isEditable(int index); } The column list and whether it was editable was really static information for the class but I wanted to keep ColumnData as an interface instead of a class, so I created an annotation for defining the column information as show below @Retention(RetentionPolicy.RUNTIME) public @interface ColumnAttributes { public String name(); public boolean editable() default false; } Be...

Blog on Scala , which is a functional programming language that runs on the JVM

The R Programming Language is used for Statistics. See Introduction to R for programmers coming for other languages

The Oracle SQL Model allows you to do a lot more things in SQL that you would normally have done in PL/SQL. You can find a good tutorial here

Bill Gates has posted lecture on Physics by Richard Feynman at the Microsoft Research website. You need IE to view these lectures

10 Promising Web Platforms , this is a list off platforms outside of the popular ones like Facebook and Myspace that could become popular.

Interesting post on how Linus Trovalds manages the Linux Kernel development process . Some of his opinions would also apply to large closed source development where the team members are geographically distributed.

Going through the list of 15 suggessions to improving usability in open source software the main problem is that too many cooks spoil the broth, A good user interface requires as much thought as does the software architecture. There have been cases where a requirement for a better user interface has required significant changes in the code across the stack because usability was not thought about upfront.

Having survived a badly run startup, which raised a huge amount of money and then went under because they spent the money they raised as if there was no tomorrow. There are many ways to fail, running a startup but few ways to succeed. 25 Internet startups that bombed