Blog Archives

Safely Loading Packages in R

January 18, 2013
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Using R snippets written by other developers can be unendingly maddening.  There are a variety of reasons for this, most of which boil down to a simple issue: most code is written such that a system must be configured in … Continue reading →

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Project Euler — problem 25

January 16, 2013
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Project Euler — problem 25

Finally, the fog lasting for days went away this morning and the sun comes out. It’s a lovely winter day. After taking a walk after lunch, I feel like doing some math. So, here comes the 25th Euler problem. The … Continue reading →

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Project Euler — problem 24

November 20, 2012
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It’s a lovely day. I took a walk around the campus after lunch. The scene was enjoyable in one deep autumn day. Before the afternoon work, I’d like to spend a few moments on the 24th Euler Problem. A permutation is an ordered arrangement of … Continue reading →

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Project Euler — problem 23

November 9, 2012
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Officially, it’s weekend. I’m solving this 23rd Euler problem just before my supper. A perfect number is a number for which the sum of its proper divisors is exactly equal to the number. For example, the sum of the proper divisors … Continue reading →

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Project Euler — problem 22

November 7, 2012
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Just had my supper. Stomach is full of stewed beef and potato.  I’d like to solve the 22nd Euler problem before tonight work (right, I’ll work late in my office). Using names.txt (right click and ‘Save Link/Target As…’), a 46K text file containing over … Continue reading →

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Project Euler — problem 21

November 3, 2012
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Project Euler — problem 21

It’s been over one month since my last post on Euler problem 20, when  I was planning to post at least one on either Euler project or visualization. So I am four posts behind; I’ll try to catch up. Tonight, I’ll solve the 21st Euler … Continue reading →

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Project Euler — problem 20

September 23, 2012
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It’s been quite a while since my last post on Euler problems. Today a visitor post his solution to the second problem nicely, which encouraged me to keep solving these problems. Just for fun! 10! = 10 * 9 * … * 3 * 2 * 1 … Continue reading →

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googleVis — Diaoyu Islands

September 14, 2012
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googleVis — Diaoyu Islands

China just announced the Diaoyu Islands baselines yesterday (US EST). Take a look at their locations (Clike here for the google map).

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Project Euler — problem 19

September 3, 2012
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I’ve been working overtime last weekend. Although I suffered little from the Monday syndrome, I still need a break. So, I’m back to the Project Euler after days of Olympic data digging. Today, I’m gonna to solve the 19th problem. You are given the following … Continue reading →

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googleVis — NASA’s exploration of Mars

August 29, 2012
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googleVis — NASA’s exploration of Mars

After generating a few interactive charts with googleVis, I realized that it’s a great way to visualize numeric data, especially multi-dimentional data. Days ago, my colleague sent me a picture taken by Curiosity from Mars. He was crazy about it … Continue reading →

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