Apr 27, 2008

Opacity

Apr 21, 2008

Nationality Name

For most counties, the nationality name usually in form of country name + suffix: -an, -ian, and -ese.
China->Chinese, Japan->Japanese, are all the east Asian the "ese" people? Let's find out with Mathematica: CountryData["Country", "NationalityName"].

From the above map, you can see it is not true at all, e.g. Korea->Korean, Thailand->Thai. Portugal->Portuguese is only "ese" country in Europe.

One thing I hear quite often is that -ese means smaller and less power as opposite to -an and -ian, -ese is used by western colonist in an insulted way. I don't know how much historic truth in this claim. Google search gives out the following:
-ian -an from Latin –ianus, meaning "native of", "relating to", or "belonging to"
-ese from the Latin -ensis, meaning "originating in"
However, it is hard to know why some countries are with "-ese", others are not.

Apr 7, 2008

Minimum Bounding Rectangle of a Point Set

Give a 2-D point set, we need to find the minimum bounding rectangle in term of area.

I read it somewhere that the minimum rectangle must always contain at least one edge of the convex hull, however, I can't find a citation now. So the algorithm can be constructed in the following way: first construct the convex hull, then rotate each edges for the convex hull to the position parallel to x-axes, then calculate area of bounding rectangle; find the minimum one of these rotated rectangles and rotate it back to normal.

Apr 4, 2008

Nonsense

The early sign of scientist self-destruction nature.


mushroom is from http://www.wpclipart.com/plants/mushroom/mushroom.png

Google Chart API

The Google Chart API lets you dynamically generate charts.

The basic format:
http://chart.apis.google.com/chart?<parameters>

Sample chart

It is the most straightforward solution for web application to display dynamic graphs. I am wondering if Wolfram can come up something similar, not the webMathematica, just a simple free image generator will be great, it is definitely a good way to get more publicity.

Apr 3, 2008

Tips: Customizing Graphplot

For a graph g, we like draw leaves in different style from nodes.


(* find leaves *)
leaves = Complement[g[[All, 2]], g[[All, 1]]];
TreePlot[g, VertexLabeling -> False, PlotStyle -> {Black}, VertexRenderingFunction -> (If[MemberQ[leaves, #2], {FaceForm[LightGray], EdgeForm[Black], Disk[#1, 0.15], Text[#2, #1]}, {FaceForm[White], EdgeForm[Black], Disk[#1, 0.15]}] &), AspectRatio -> 0.3]

The tip is in VertexRenderingFunction, Text[#2, #1], #2 means the label, #1 is coordinates.