DIY折衣板
Funny.
Saturday, July 15, 2006
Tuesday, April 18, 2006
Fwd: Lunar2006 Calendar File in ICalendar Format
Now it can be accessed from http://kent.woo.googlepages.com/2006Lunar.ics
or http://icalx.com/public/kunwu/lunar2006.ics
or http://icalx.com/public/kunwu/lunar2006.ics
I found this file on this site http://liyingri.googlepages.com/2006Lunar.ics
Look into details of each day tips.
Look into details of each day tips.
Wednesday, March 22, 2006
CoDeen -- A CDN on PlanetLab
It's a wonderful project. Many nodes involved.
Here's the main link
http://codeen.cs.princeton.edu/
And the nodes list.
http://fall.cs.princeton.edu/codeen/
Here's the main link
http://codeen.cs.princeton.edu/
And the nodes list.
http://fall.cs.princeton.edu/codeen/
Tuesday, March 21, 2006
Verify the 72 Rule
Mimi told me a 72 rule last night. How many years does it need to double your balance while given a fixed interest rate? Using 72 divided by the interest rate. That it is.
The rule is verified by plotting the curves. Here's the m file for Matalb (v6.5). And some figures can be found below.
The rule is verified by plotting the curves. Here's the m file for Matalb (v6.5). And some figures can be found below.
% Years to double your balance
% WUKun, 21March,06
% function definition
fTheory = inline('log(2)/log(1+x)');
f72Rule = inline('.72/x');
% interest rate: 1% ~ 10%
interest = linspace(.01, .10, 100);
% years
for i = 1:length(interest)
yTheory(i) = fTheory(interest(i));
y72Rule(i) = f72Rule(interest(i));
end;
% plot
figure(1);
plot(interest, yTheory, 'k', interest, y72Rule, '-.r');
legend('Theory Curve', '72Rule Curve', 0);
grid on;
xlabel('Interest Rate');
ylabel('Years');
title('Years to double your balance');
%%%%%%%%%%%%%%%%%%%%%%%%
% -- What's about extend the scope of interest? --
interest = linspace(0.01, 10.0, 100);
% years
for i = 1:length(interest)
yTheory(i) = fTheory(interest(i));
y72Rule(i) = f72Rule(interest(i));
yError(i) = (yTheory(i)-y72Rule(i))/yTheory(i);
end;
% plot
figure(2);
subplot(1,2,1);
semilogy(interest, yTheory, 'k', interest, y72Rule, 'b', interest, yError, 'r');
legend('Theory Curve', '72Rule Curve', 'Error', 0);
grid on;
xlabel('Interest Rate (1%~1000%)');
ylabel('Years (log)');
title('Years to double your balance, Haha, the terrible interest!!!');
subplot(1,2,2);
plot(interest, yTheory, 'k', interest, y72Rule, 'b', interest, yError, 'r');
set(gca, 'xlim', [1 10]);
legend('Theory Curve', '72Rule Curve', 'Error', 0);
grid on;
xlabel('Interest Rate (100%~1000%)');
ylabel('Years');
title('Years to double your balance, Haha, the terrible interest!!!');
Friday, January 20, 2006
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